Road construction is an intricate process that requires understanding the layer underneath, also known as the sub-grade, to ensure the road is durable and can withstand heavy loads and different environmental factors. Sub-grade road models help engineers visualize how the ground looks and predict how it will respond to traffic over time. They are also crucial in enhancing construction planning and operations, particularly for curb machine efficiency.
Understanding Sub-Grade Road Models
A sub-grade model refers to the representation or design of the sub-grade layer in construction. The sub-grade is the layer of material that lies beneath the pavement structure, specifically the soil and any other materials that support the road surface. A well-designed sub-grade makes sure that a road is stable and durable. When it comes to construction planning and project execution, sub-grade models are important for helping engineers estimate how well a road or pavement will withstand different traffic loads and weather conditions while minimizing maintenance and repairs.
Key aspects of sub-grade road models include:
Material composition: Sub-grade materials are typically soils that can be clay, silt, sand or gravel. Their properties are crucial to road performance.
Design parameters: The model defines various parameters, including the thickness, strength and compaction levels required for durability.
Stress and strain behavior: Sub-grade models can simulate how the sub-grade layer will react to the stress of traffic or different weather elements.
Geotechnical analysis: Engineers use sub-grade models to interpret data from soil tests and determine the best treatment methods to improve the sub-grade’s strength.
How Do Sub-Grade Road Models Enhance Construction Planning?
There are several benefits of using sub-grade road models in construction planning for roadwork and highway projects, including:
Improved accuracy: Sub-grade models allow engineers to analyze various soil types and conditions, leading to designs that are specifically tailored to the site’s characteristics.
Design optimization: With accurate models, engineers can determine the appropriate thickness and materials for the pavement layers above the sub-grade. This information helps ensure that the road or pavement can handle loads and withstand various environmental conditions.
Identification of potential issues: Understanding the sub-grade’s capacity to support traffic loads is crucial for preventing pavement failure. Sub-grade road models can help identify potential problems, such as excessive settlement, before they occur. They allow contractors to take necessary measures to deal with these issues.
Cost efficiency: By accurately modeling sub-grade conditions, engineers can optimize material usage and construction methods, maximizing available resources and reducing costs.
Project timelines: Accurate models allow for better planning and scheduling, reducing the likelihood of delays caused by unforeseen issues related to the sub-grade.
Maintenance planning: Understanding how the sub-grade will perform over time allows for better maintenance activity planning. This can help promote road safety and minimize disruptions.
Facilitating Efficient Curb Machine Operations
Curb machines are used to efficiently install gutters and curbs along drainage systems, sidewalks and roads. Sub-grade road models significantly contribute to curb machine efficiency by providing insights about the condition of the soil, leading to more precise and consistent curbing outcomes.
By understanding the strength and stability of a sub-grade, engineers can determine the appropriate depth and width of curbs. This accuracy prevents curbs from shifting over time, making them more durable. When contractors get to know which areas of a sub-grade are weaker, they can adjust the weight distribution of the curb machine to avoid excessive pressure on the soil and prevent damage.
Sub-grade models can be used to identify areas that may be deteriorating or experiencing excessive stress. Engineers can use this information for targeted maintenance and repairs to prevent more damage and maintain the structural integrity of the curb. They can also identify the best materials for the curb to enhance its performance and durability.
Tools and Technologies for Creating Sub-Grade Road Models
Tools and technologies used to create accurate sub-grade road models include:
Computer-aided design (CAD) software: CAD programs like AutoCAD or MicroStation can create detailed road designs, including the sub-grade layer. These designs are turned into 2D and 3D models of the road and its components.
3D modeling software: Specialized 3D modeling software, such as Civil 3D, is designed specifically to create detailed models of the sub-grade and pavement structure. They enable the visualization and simulation of how the sub-grade will perform under various loads and environmental conditions.
Geographic information systems (GIS): GIS software is used to organize, manage and analyze spatial data collected from the field. These tools allow engineers to incorporate real-world geographic and topographic data into sub-grade designs, ensuring the foundation of the road is ideal for that specific natural landscape.
Geotechnical analysis software: These specialized tools help engineers analyze soil properties and create models for sub-grade layers based on site-specific geotechnical data.
Ground penetration radar (GPR) system: GPR can provide information about subsurface conditions, such as soil layers, by producing images of subsurface interfaces.
The accuracy and effectiveness of sub-grade road models are essential for the road’s functionality and durability. Sub-grade models must consider the properties of soil, traffic loads, environmental factors and construction practices — all of which can be different for every project. Implementing these models in construction projects comes with various challenges.
Soil Variability
A sub-grade is comprised of natural soils whose properties, such as strength, compaction and moisture content, can vary significantly even within small areas. This variability makes it difficult to create uniform sub-grade models that account for changes in soil conditions on a road.
To address this challenge, contractors can conduct detailed soil testing across multiple locations to identify variations in soil properties. They can also use adaptive modeling techniques to determine the appropriate sub-grade treatments in different areas based on localized soil characteristics.
Inaccurate Data Collection
Sub-grade road models are heavily reliant on accurate data, whether environmental, geotechnical or topographical data. Inaccurate data from surveys or soil tests can lead to incorrect models, causing problems when constructing the road.
Advanced technology solutions, such as LiDAR and GPS-based total stations, can enable more precise topographical data collection. It can also be helpful to perform soil tests at different points along the road to minimize the risk of inaccuracies.
Environmental Factors
Environmental conditions, such as drainage patterns, seasonal weather variations and water table levels, can affect sub-grade performance. Excessive moisture, for example, can weaken the soil and cause road failure. This consideration means that it can be difficult to predict long-term performance based on historical data.
Proper drainage design can solve this challenge. Drainage systems can be incorporated into the road design to prevent water from accumulating in the sub-grade. The materials used in the sub-grade should also be resilient to various weather conditions.
Long-Term Performance Prediction
Predicting how the sub-grade will perform over the long term under varying traffic loads and environmental conditions can be challenging, leading to uncertainty in design decisions. Determining how future traffic loads will impact the sub-grade is not straightforward, especially for roads that might see rapid changes in usage or unexpected surges in traffic volume.
To mitigate the risks of this challenge, models must also account for future maintenance needs. Engineers and contractors can simulate different scenarios on the road and see how it would hold up to help prevent disruptions or unexpected costs.
The Role of Sub-Grade Road Models in Sustainable Construction
Sub-grade road models contribute to sustainable construction practices by optimizing the foundation of a road structure. A well-designed sub-grade contributes to sustainability in the following ways:
Efficient use of materials: Sub-grade road models ensure that the correct type and amount of materials are used in road construction. By optimizing the use of natural resources and minimizing excess material usage, sub-grade models support sustainable resource management, reducing the number of environmental impacts caused by sourcing construction materials.
Waste minimization: Advanced sub-grade models ensure that only necessary quantities of materials are used and that risks are mitigated, reducing the need for corrections during construction. As a result, construction teams leave less waste material, whether from unused materials or from over-digging.
Improved water management: Drainage analysis is carried out when creating 3D paving and road models to predict water flow. It contributes to the design of proper drainage systems that prevent the risk of flooding, erosion or waterlogging after the road has been constructed.
Contact Take-off Professionals for Detailed Sub-Grade Road Models
Sub-grade road models play a critical role in successful construction planning and operations. At Take-off Professionals, we create 3D data for machine control and layout, including 3D utility layouts, grading surfaces and utility trenches. We can develop sub-grade models that facilitate efficient construction projects.
With our accurate models, you will save time and streamline your road work processes. Our team of industry experts has what it takes to provide excellent client service and help meet your project needs. Contact us today to learn more about our services.
Construction projects require detailed planning and meticulous execution. To achieve this, contractors and engineers must understand the existing conditions of their construction zone. Documenting existing conditions in construction projects serves as the foundation for creating accurate models. It enables better decision-making and improved resource allocation, which in turn leads to successful projects that meet the needs of both clients and end users.
What Are Existing Conditions in Construction?
Existing conditions refer to the state of a construction site and its immediate surroundings before construction work has begun. They involve aspects such as:
Existing structures: The current state of buildings in that location, including walls, roof systems and foundations.
Topography: Involves the shape and elevation of the land, including natural drainage, slopes and other features.
Soil conditions: The composition, stability and bearing capacity of the soil.
Utilities: Locations and conditions of existing water, gas, electrical and sewage lines.
Understanding existing conditions is essential for planning, designing and executing construction projects. It can also influence the project’s timeline, cost and scope. For example, when planning a new building adjacent to an existing one, it is crucial to assess the structural integrity of the current building, its foundation and any potential impacts on neighboring properties. By comprehending existing conditions, engineers can design site layouts that complement the site. They can also identify potential hazards, such as unstable structures, and implement measures to address worker safety.
Methods for Documenting Existing Conditions
There are various methods and technologies used to document existing conditions.
Surveying
Surveying involves precisely measuring and mapping a site’s physical features. It is critical to ensure that new construction is designed and executed properly. Surveying is often used to determine property boundaries, establish a site’s topography and locate other utilities, structures and important site features.
Land surveyors use various tools and techniques, such as global positioning systems, to measure distances, angles and elevations accurately. The resulting data is used to create detailed site plans or topographic maps that serve as the foundation for product development. Surveying can be used in conjunction with other documentation methods, such as 3D modeling or building information modeling (BIM), to clearly showcase the project’s starting point.
Photogrammetry
Photogrammetry involves a comprehensive photo scan to collect data for generating a 3D model. By taking multiple overlapping images from different angles, photogrammetry software can analyze the photos and calculate the exact positions and dimensions of objects, producing very precise representations of a structure.
This method can be used to capture both large-scale areas, such as construction sites or landscapes, and smaller details of objects and buildings. It can be especially useful in creating as-built documentation for construction, where accurate records of architectural features are needed for renovation or expansion. When performed correctly, photogrammetry provides precise measurements and detailed models, making it ideal for documenting existing conditions.
LiDAR
Laser scanning, also known as light detection and ranging (LiDAR), is a technology that uses laser beams to measure distances between the scanner and surfaces. It then creates a detailed 3D representation of the site or building. The data collected from laser scanning is transformed into a point cloud, which can be processed into 3D models. This method is useful for capturing irregular surfaces or large sites with intricate details that are difficult to document manually.
Given how accurate this method is for documenting existing conditions, LiDAR is ideal for projects that need highly precise records, such as infrastructure upgrades, renovation projects and building restorations. It is also very efficient, capturing an extensive number of data points in just a few minutes, reducing the need for repeated site visits.
Building Information Modeling (BIM)
BIM is a digital method that uses a set of software tools to create digital representations of a building or infrastructure project. As one of the emerging trends in the construction industry, BIM combines engineering and construction data to create comprehensive 3D models. For existing conditions, this method can create a virtual experience of a monument, bridge, building, road or highway before it is constructed.
BIM models are highly interactive and can be used to simulate potential changes or identify conflicts between new and existing conditions. It also comes in handy in large, complex projects where various stakeholders like engineers, contractors and architects need to collaborate by providing all parties with access to accurate, up-to-date information.
Tools and Technologies for Accurate Documentation
Accurate modeling of existing conditions allows architects and engineers to integrate new designs seamlessly with the existing environment. As a result, new construction complements or enhances the current structures and landscape. Here are some tools and technologies that facilitate the accurate documentation of existing conditions:
Laser scanning point cloud manipulation software: This software processes data captured by laser scanning equipment to create point clouds, which are 3D representations of physical environments made up of millions of points.
3D modeling software: Software such as Revit and AutoCAD can be used to create 3D models from survey data.
Conventional surveying equipment: Traditional surveying equipment includes tools like theodolites, total stations and GPS devices used to measure and map land and structures.
Infrared cameras: These devices can be used to detect thermal anomalies and identify potential issues like moisture and structural defects.
Challenges in Capturing Existing Conditions
Documenting existing conditions in construction projects comes with several challenges that can vary depending on how complex the site is, the tools used and other environmental factors. The following are common challenges faced in capturing existing conditions:
Limited accessibility: In many construction sites or buildings, certain areas may be difficult to access for documentation due to physical constraints, safety hazards or logistical issues. Features located underground or concealed features can be difficult to assess without specialized equipment or techniques.
Complexity: Capturing the existing conditions of large, complex structures can be time-consuming and require specialized equipment and expertise. It can also be difficult to document interconnected systems such as plumbing and electrical systems.
Incomplete documentation: In some cases, key information about the construction site, such as underground utilities and foundation details, may be missing.
Environmental factors: Adverse weather conditions, such as rain or high winds, can hinder data collection and analysis as well as pose safety risks for surveyors and equipment.
Human error: Areas where human error can occur while capturing existing conditions are misinterpreting site features, taking incorrect measurements or failing to capture key details. Even with advanced tools, mistakes during data entry or when converting raw data into usable formats can lead to misleading information.
Technological limitations: Traditional methods, such as manual surveys, may not provide sufficient details or accurate results. While technology like laser scanners greatly improves the accuracy and efficiency of documenting existing conditions, it can be expensive to procure or requires specialized expertise to operate.
Benefits of Accurate Existing Condition Documentation
Accurate documentation of existing conditions is beneficial in a number of ways, including:
Improved project planning: Accurately documenting existing conditions provides engineers and contractors with a clear understanding of a site’s current state, which helps them create effective designs and layouts. Information about natural features like slopes or vegetation allows them to incorporate these elements into their plans, improving the functionality of the final build.
Enhanced safety: Knowing the location of structural vulnerabilities, unstable soil conditions or potentially hazardous conditions allows for proper mitigation strategies to be developed, ensuring the safety of people working on the construction site. In addition, with detailed knowledge of the site’s conditions, project managers can ensure all the work is performed in compliance with local building codes and safety regulations.
Greater decision-making: Documenting existing conditions provides a clear view of a site and its existing structures and materials, allowing stakeholders to make informed decisions about a project. For example, they can make more accurate cost estimates, preventing unexpected expenses.
Improved communication and collaboration: When architects, engineers, contractors and clients have the same accurate information about existing conditions, they are able to collaborate better. For instance, they can easily align expectations and avoid misunderstandings about the project’s scope, design and timeline.
Reduced errors: Accurate documentation of existing conditions helps pinpoint potential issues or defects in a site or structure, which can mitigate risks during construction and avoid costly mistakes.
Better efficiency: Documenting existing conditions can prevent delays by ensuring the project team has the necessary information to proceed efficiently. By identifying potential challenges ahead of time, the need for mid-project change orders is minimized, helping keep a project on schedule.
Document Existing Conditions Accurately With Take-off Professionals
Accurately documenting existing conditions is essential in construction and architectural projects to ensure that design and construction processes are based on reliable, precise information. At Take-off Professionals, we have the tools, technology and expertise to help you precisely capture existing conditions for accurate construction modeling.
We can work with you on various levels to meet your specific project needs. If you want to be more accurate with your data, we have the ideal solutions for you. Contact us today to learn more about how you can transform your projects with construction modeling and how integrating existing conditions documentation can transform this process.
Technology has led to various advancements in different industries, including construction. 3D modeling, for instance, is one of the most impactful forms of technology used in construction. 3D models improve accuracy and efficiency by assisting in strategic site layout planning, including utility and landscape mapping. The use of this technology simplifies the site layout planning process and improves accuracy.
Understanding Site Layout Planning
Site layout planning is a critical aspect of construction project management that involves strategically arranging various elements on a construction site. This process ensures that resources and space are used optimally and construction activities are conducted efficiently, safely and in compliance with relevant regulations. Civil contractors often use computer-aided programs to plan and visualize a construction site. Traditionally, this was done using 2D methods, but it is now enhanced by 3D modeling.
The main elements involved in site layout planning include:
Site analysis: Before creating a layout, a thorough site analysis is conducted to assess various factors such as the topography, soil conditions and existing infrastructure.
Positioning of temporary facilities: This step involves identifying the site facilities that will be required and where to place them. These facilities include site offices, storage areas, machinery and equipment zones and worker facilities such as break rooms and sanitation facilities.
Access and traffic management: Access requirements should be considered after the necessary facilities have been identified. This includes ensuring workers can move safely between work zones and welfare facilities. It also includes considerations of the routes that trucks and machinery will follow to move materials in and out of the site. The placement of utilities such as gas, electricity and water must also be considered when planning a site layout.
Materials handling and storage: To prevent delays, materials must be placed to optimize the handling process. They should be stored close enough to the work site, but not in a way that hinders workflow. Secure areas should also be provided for fragile or hazardous materials, considering environmental conditions like heat or rain.
Safety and compliance: Safety plays a critical role in site layout planning, with features such as fencing and barriers as well as emergency access.
Optimizing workflow: The layout should streamline the construction process, ensuring smooth transitions between different phases. It involves placing machinery where it can be used efficiently without needing frequent repositioning and material flow, where materials can be efficiently moved from storage to the point of use.
The Role of 3D Models in Site Layout Planning
3D models play a crucial role in site layout planning by providing a comprehensive, detailed construction site representation. These models enable project stakeholders to visualize the site layout in a realistic and immersive manner. By leveraging 3D technology, engineers can create digital replicas of the site, complete with accurate terrain features, existing structures and proposed elements. In most cases, the site layout model includes:
Zones for particular activities
Site offices
Welfare facilities
Off-loading, temporary storage and storage areas
Sub-contractor facilities
Car parking
Utilities, including electrical power, lighting, water distribution, drainage and communications technology
Temporary works
Areas for the construction of mock-ups for testing
Fabrication facilities
Emergency routes
Entrances, exits and other access points
Waste management and recycling areas
Site hoardings and existing boundaries
Signage
3D models enable accurate spatial planning via precise measurements and placements of elements on the site. Contractors can use these models to ensure that all components, such as buildings, roads, utilities and landscaping features, are accurately positioned. They can also check to ensure the site layout aligns with project requirements. Visualizing the site layout in a 3D environment helps optimize how the space is organized, ensuring efficient use of space and resources. It also allows for better decision-making and reduced errors in site layout planning.
Utility Mapping With 3D Models
3D models integrate utility mapping by precisely planning the placement of essential services. For example, you can map where to place electrical equipment, such as light poles, electrical service slabs and connections for electrically powered elements like decorations, kiosks and signs. With 3D models, electricians can set these connections up accurately and quickly.
Other utilities you can map using 3D technology include natural gas lines, water and wastewater piping and gutters. The information provided by the models gives crews confidence that they are making the most efficient placement. They are better prepared since they know where every element will go, helping avoid the need for re-digging in later stages. You can include several other elements in a 3D model, such as benches and curbing.
Landscape Mapping and Planning
Landscaping projects are becoming more demanding and complex, which is why data accuracy is increasingly crucial. Technology has provided landscape architects with a unique opportunity to incorporate new standards into traditional methods.
3D models allow landscape architects to create more accurate, data-driven designs that meet the highest operational and aesthetic standards, giving them an edge over competitors. They can integrate data to develop dynamic and detailed representations of projects. 3D models aid landscape architects in the following ways:
Visualization: 3D models can be useful in visualizing and planning landscape features to ensure they complement the overall site design.
Cost reduction: With the correct data, you have the information you need to maximize the financial resources available in each project.
Efficiency: Data processing and 3D modeling services enable you to clearly define your project’s specifications and scope.
Communication: You can use 3D models to properly articulate your ideas to stakeholders.
A lot of data needs to be collected to create these 3D models. To compile information from different sources, a solution is needed that can transform the collected information into usable data, which can then be used to create construction documents and site plans. Technology that’s often leveraged in data preparation for creating 3D models includes:
Light detection and ranging (LiDAR) solutions: Create detailed 3D models using advanced LiDAR technology that account for different geographies.
Photogrammetry mapping: Enhance the accuracy of construction projects with integrated photogrammetry mapping.
Benefits of Using 3D Models in Site Layout Planning
There are many benefits of using 3D models to plan site layouts, including:
Improved decision-making: 3D models allow construction contractors to visualize different potential outcomes with varying site layouts. This capability enables them to assess the impact of factors such as functionality and cost when making decisions, leading to more successful projects.
Increased efficiency: 3D models streamline the site layout process by providing a detailed visualization of the project. The visualization allows designers to experiment with different layouts and make informed decisions, which saves time and resources.
Enhanced collaboration: With 3D models, construction workers, engineers and architects can access a realistic representation of the site layout. They are able to easily understand and contribute to the planning process, reducing misunderstandings and improving communication.
Mitigated risks: Using 3D models helps pinpoint potential risks before construction begins, such as clashes in building systems. By identifying issues early in the planning stage, civil contractors can take a proactive approach to reduce the likelihood of delays during construction.
Improved communication: Traditional 2D site plans often leave room for misinterpretation. However, 3D models are more detailed and offer a more accurate representation of a site layout. They are also useful in explaining complex design features and answering questions clearly.
Enhanced creativity: 3D models empower planners to explore creative opportunities and experiment with different design solutions. They are able to visualize site layouts from different perspectives and angles, making changes as they go to see the impact on the overall layout.
Reduced project costs: Using 3D models minimizes the need for rework and changes during construction, allowing for projects to be completed within budget. Since potential issues will be identified earlier on in the planning process, it can reduce costs related to rectifying errors.
Contact Take-off Professionals for Accurate 3D Models
3D models are a valuable tool that promotes informed decision-making during the site layout process. At Take-off Professionals, we transform your data into accurate 3D models to help you achieve the best results possible. We have a team of qualified technical staff and engineers who are experienced in creating 3D models for site layout planning, so you can rest assured that your projects are in the hands of experts in the field. Many of our competitors use subcontractors, but our team is made up of full-time employees who take care of all aspects of building 3D models.
We’ve been in business for over 20 years and have built a solid reputation for providing exceptional customer support, paying attention to detail and delivering accurate and timely results. To simplify placing a work order and reduce turnaround times, we have an exclusive platform where our clients can add files, notes and other important information that would be useful in 3D modeling projects. Contact us today to learn more about how our 3D models can impact site layout planning and improve your project outcomes.
The Bell Helmet Company once had a magazine ad with the statement, “If you have a 5-dollar head, get a 5-dollar helmet.” Wise words when you think about protecting your brain. The interwebs have done a great service to us; we now have experts in every corner of the world. I admire some of them but do an eye roll with many. As one of the original innovators in the industry, I’m not pulling rank, I am speaking from experience. I just do not like to hear bad information being passed off as truth.
Regarding those who advertise low-cost data, I have but one thought: If your work was worth more, you would charge more. So many people are not invested in making a good product, but just making a product. I have spent my career working on delivering data in the fewest mouse clicks possible. We like to bill for work done efficiently by trained professionals who have been trained by experienced mentors familiar with a lot of different data issues. When the experience issue gets brushed aside as a “nothing burger” by more recent entrants to the data industry, one has to look at the actual time it takes to decode and properly set up a project.
Many times when inexpensive data gets built, it is just converting a surface built by the engineer at some point in the design. This is usually done to get a rough dirt number so that some quantities can be put on the plans. When doing a takeoff and I was close to the engineer’s numbers, I went through things again. Those quantities are usually never close. The surface is not only a few changes behind the plans, it lacks the detail for successful grading. Here is why proper data takes a bit of time.
Initial Data Files
We receive the plans and CAD in addition to a work order for the job. We often find that the plans and CAD are a mismatch. Not a big deal. Just find out which of the two is correct, get the current file and we are good to go. For every job we do, the files get touched by no fewer than three software platforms. It is not cheap to have all that horsepower, but we can do a more efficient, competitively priced job with them. We need to read the plans and relevant specifications to insulate our client from issues. We want no surprises. Notes on the job guide our work, then we start building.
The Big Picture
I will use a sample project to give you an idea of what good data, coupled with 25 years of experience, looks like. The data engineer working on the job has a deep bench of talent to call on for advice. A great advantage that goes a long way in securing a good job for our clients. Here are the basics:;
The entire job consists of a building with a basement, parking for 200 vehicles, and a long entrance road.
There is detailed landscaping along with a lot of drainage work, (wet part of the country).
We also need to build an initial water management surface, as all the water needs to stay on the project. Watershed pollution prevention.
Initial CAD Work
We have detail sheets that we populate for our clients. Surface density, line colors, file types, and delivery method are a few of the things that make a job easier for our clients’ field crews. As a former field hand, I like to be in their corner and do everything possible for them. Five minutes of work in our office on the computer saves 30 minutes balled up in the cab of a work truck, trying to change something. Here is the process.
Civil 3D files can be feature rich. That is good news for somebody doing poor work and just converting a surface. In our world, that is something we delete to make the file smaller.
Lines have become critical. A grade checker will want a 3- foot back of curb 3D line to set string or hanging forms. A blade hand wants to snap on an edge of pavement line to shift the blade 2 feet behind the curb for slip former access. All of these lines need to be in the correct direction, void of any overlaps and breaks. That takes time.
With the paper plans ruling, we need to confirm that the job looks like the CAD; this can be time- consuming and frustrating. The best that one can hope for is a spot check with budget data work.
In the early days, we worried about file sizes, but not so much anymore. It still makes sense to show only the lines necessary to complete the work. Text needs to be simple and in a format that does not steal bandwidth from a controller.
Surface Components
Since the beginning of the data business, we have used the same elements for building data. Each of these must be carefully created and work with the other parts.
2D Lines
Contour lines are really 3D lines as they are elevated. But because it is all the same elevation, we call them 2D lines. How those lines are produced is something the model builder will find out if they are doing their job.
Sometimes points are placed on the surface and contours are produced later.
Contours can be drawn by hand to show intent. That means you cannot use them on the surface, but they are nice to look at.
Contours are made first to show slopes and sheeting water, usually in a parking lot. They are interrupted later for islands and other features.
In our example shown above, the contours were drawn in later to show the general slope of the parking lot. The slope arrows provide some faint clues on how the water is moving. This one took some time to get right.
3D Lines
When doing curb, the elevation of a line changes. We first need to plug in the numbers from the plans, then fix issues that are obvious.
If there are things that do not make sense, we need to run a request up the ladder and get more information.
In our sample project, the slopes in the ADA parking areas are out of spec. This is not an issue; we check the percentages and make them right. If they do not fit, we need to talk to someone. A quick once- over of an engineer’s surface will not catch these small details.
There are a lot of things we can do with these lines. Offset the flow line to get top back of curb, even extend that line for staking. This requires us to create lines, which cannot be done from a surface found in the original CAD.
Points and breaklines
I have always used points to create an absolute elevation. Think of the rim of a storm grate.
Points are used by our clients to layout improvements.
Points are useful for curb radius points as well as footings and building corners.
We will do layout of light poles, playground equipment, electrical lines, and SES pads. The list is long.
Breaklines are used to make a surface respond the way you want it to. Triangle linking is indiscriminate and these lines make features look like the design. This could be from a simple ditch to parking lot flow lines.
They become the final tool to get things looking right. They are a necessary and sometimes frustrating tool. Too many breaklines and the surface is strained, too few and details get lost.
Summary
In order to use a surface made by someone else, the above issues would need to be addressed. It takes longer to take things apart and put them back instead of doing it right the first time. Cheap data uses information that is not correct. A few checks and it lands on your site. Instead of a surface you have a minefield, not knowing where the bad spots are. There is still a culture of “fix it in the field.”. This does happen when provided with too little information, but it is the rule when dealing with marginal work from less -experienced model builders.
I, in no way, am faulting engineers for this. Any surface made by them is for a different purpose. It is the job of the model builder to get inside the plans and understand the site from a singular point of view. Will it perform as intended? Years ago, I wrote an article in Machine Control Online Magazine. The title was “You Pay Us to be Nervous.” You just cannot do a good job in a couple hours.
Spoiler alert, I’ll give the answer first, then explain. As a major data engineering firm, we require the regular use of Civil 3D. For those of you that provide data for your own company, you can usually find workarounds to save money. Once you have the budget to acquire Civil 3D, you’ll have to learn how to effectively use the program.
Personally, I do not know the program and never really liked it that much. It is not very intuitive and took a long time to learn mostly because the classes were taught by geeky users who were thrilled at how many mundane things could be done with the software instead of doing work. But that is a discussion for another day. The most common task I would perform would be the conversion of a MicroStation surface to something we could use in other programs. I got some training, and everything worked great for a few months. Then the software was upgraded, and my cheat sheet was worthless. Back to the drawing board. I had to perform other tasks as well in MicroStation that had varying degrees of success with upgrades.
What are the benefits and risks of investing in Civil 3D?
Remember, you may know how to do something today, but an upgrade may change that routine. Here are some things to keep in mind.
To license a seat of Civil 3D, you are looking at about $2,500.00 per year.
You can rent the program with tokens. More on that later.
If you do not know what to do, training will be required.
It is a frustrating program to use and difficult to learn a few commands without being familiar with the structure of commands and processes.
It takes at least a week or two of training to get used to the program to perform your desired application.
Training may not be targeted to your needs and could require you to learn a lot of things you will never use.
CAD Tokens
The use of tokens for Autodesk Products is a new option to purchasing software. I like the concept because I use Revit on a sporadic basis and cannot justify a yearly subscription. A look into the cost of Civil 3D tokens resulted in the following data.
Tokens are $3.00 each
Civil 3D costs 9 tokens ($27.00) per 24-hour period
Shut down the program during the 24-hour period and the tokens are considered spent for the session (Pro Tip).
If you are comfortable using Civil 3D to perform the required tasks, then this is a good deal. If you are new to the program, or a few releases behind, it will be better to license a seat and access the program on a regular basis for training and use. It will be much less frustrating.
That brings up the issue of training. The wonderful thing about Civil 3D, and all Autodesk products, is the wealth of training resources on the web. Do some research, as the quality varies widely, and certain You Tube channels and websites have different areas they cover. I will start with a search on what I am looking for and drill down a couple of rabbit holes until I get to the information I need.
Let us say I want to get rid of splines in a drawing. They make a mess in non-CAD programs, and it is best to convert them in CAD. A quick search gave me a tip from the Autodesk site. Quick and easy.
I will also save video tutorials from various sites, and then bookmark those sites to reference as needed.
These are obviously not crazy deep dive commands and once you go through them a few times you will remember how to use them. You can also refer to my article on “Seldom Used Commands” that shows how to build a log and cheat sheet to speed up the process.
After you have convinced yourself you cannot live without Civil 3D, or you are trying to get somebody else to buy it, what things can you do with it that cannot be done in non-CAD programs?
I must first warn you that non-CAD vendors will tell you that they can import CAD elements and that is not always the case. When all you have is a hammer, every problem looks like a nail. I regularly work on CAD files for our staff and extract items that come in messed up. You sort of do not know what you are missing with importing tools used for outside files. To test that idea, verify the import looks just like the PDF plans, there will usually be some items missing or corrupted. This is not always a bad thing but miss one good layer of spot elevations and your frustration will make you long for a seat of Civil 3D. Go and spend a few tokens and make it happen.
What Can You Do With CAD?
Here are a few of the things you can do well in CAD that may not work as good on other platforms.
Splines: I mentioned this before, but they can cause real issues if not converted to polylines.
Blocks: CAD blocks do not always import well and sometimes not at all. You can Burst or Explode the blocks.
Non-CAD programs can only Explode if they import the blocks. The Burst or explode is a whole article on its own, research it if you are interested.
Alignments: Civil 3D corridors are feature rich elements that we do not use. Our clients pay us to make the corridors in the non-CAD software they use. We can, however, extract the alignments and use them after checking their accuracy. It’s a great tool for long roads and rails.
Surfaces: A lot of existing ground surfaces are Civil 3D surfaces and do not import well into some non-CAD programs. A little work in CAD makes things easier.
Text: M-Text can cause issues on import due to the sizing attribute it gets in CAD. Changing settings of these will make them work better.
Leaders: Sometimes not a big deal but dense data has a lot of arrows and knowing where text points are can help. The problem can be the leaders are dynamic in CAD and will not appear on import.
This is a screenshot of the dropdown menu for Quick Select. These items should be made basic CAD elements if possible to improve the import of the data and for faster refresh rates on the screen.
There are more examples I deal with daily, but these are just a few of the most common ones with easy resolves. For help on your next big project, don’t hesitate to give us a call at (623) 323-8441! Our expert engineering staff is here for you.
Creating an exact earthwork estimate is an essential first step to many takeoffs. You want a bid that accurately reflects the cost of labor and materials so you can get the project fee you deserve and minimize financial risks. At Take-off Professionals, our experienced team of engineers creates precise earthwork estimates based on your designs.
This post will explain what earthwork estimates are and the three methods we can use to create them.
Fundamentals of Earthworks: Excavation and Embankment
Earthwork is the engineering process of moving, removing or adding soil, rock or other materials to change a specific location’s topography. To create a 3D earthwork calculation, compare the location’s current topography with the contractor’s proposed design. The process of creating an accurate earthwork estimation consists of calculating how much material the contractor will need to add — or fill — and take away — or cut.
Cutting is removing material from the site, and filling refers to adding material. Both are crucial for creating the topography reflected in the contractor’s design. Engineers will calculate the cut and fill quantities to reach a mass balance and use that mass balance to provide an accurate earthwork estimate.
Elevate Your Project Efficiency with Accurate Earthwork Estimates
At TOPS, we deliver precise earthwork estimates and essential 3D data to drive your project forward. Our models aid in enhancing project efficiency and accuracy, regardless of project size, enabling successful completion.
There are three main estimating methods that engineers can use when creating 3D data for earthwork in construction. These methods calculate the dirt and material quantities required while providing mass haul analysis for the construction site. However, some are more accurate than others.
Method One: The Average End-Area Method
We typically use the average method for smaller projects that require us to ascertain the levels at all grid points. Because this method is the simplest of the three, we can only use it when a project requires either filling or cutting. The average method provides inaccurate estimates if you use it for projects that use both cutting and filling.
Method Two: The Grid-Cell or Block Method
Our team uses the block method — also called the division of square method — to determine volume for medium-sized projects that require leveling. The block method is more straightforward than the section method and more accurate than the average method. You can expect some margin of error when using the block method on projects involving both filling and cutting, but much less than the average method.
Method Three: The Cross-Section Method
The section method is the most complex and precise way to calculate an earthwork estimate. We use this technique when working on large-scale projects, such as dams, railway systems and roads. Although the section method requires many steps and more complicated calculations, it’s the best method to ensure a precise estimate that will save you money.
Precision Earthwork Estimates with Take-Off Professionals
Our team of full-time engineers is on hand to provide you with precise earthwork estimates and essential 3D data. Contact us to learn more about our products or request a quote for our earthwork services.
This update will go over the newer concepts for design/build on a civil site.
These concepts have done a lot for large roads and in the vertical world where tenant build outs change daily. Generally, engineers that do not have enough staff and are worn down will welcome input from you and your staff. There are several considerations you need to address for this type of relationship.
Beware of a CMAR (Construction Manager at Risk) projects. They can be profitable but need to be fully vetted on the front end. Change orders are usually not an option. These contracts are an effort by the owner to get fixed price work so know what the project entails.
For the civil portion of a project that is done in close contact with engineers and owners, things can go fast. Changes are easily approved, so be sure you propose answers. After all, this is a team job, and you will be tasked with solutions that keep the job on schedule and budget.
Money becomes more transparent. The billing is at cost plus, or a fee above agreed upon operating and materials costs. It’s not a problem, just a different approach to billing and verifying pricing. Price increase adjustments for material cost increases need to be included.
We have all been there. Get a set of plans, open them, take a look, and wonder what possessed the team responsible to perform the way they did. I started my career in the offices of a developer/builder. I got to see firsthand how the process goes, as well as the changes that must happen. The journey often ends up with something completely different than originally planned.
Development Types
There are two types of builder groups; public and private. For this discussion we will look at private work. Private work can be further broken down into commercial and local. This article covers commercial builders.
Commercial Development
In the civil construction world, commercial development relates to projects done by a large company in different geographic areas. Think of a big box store or restaurant.
Here are some general specifications:
They have centralized operations and often work on sites they may never visit.
Their staff does a lot of projects. Operations are streamlined and efficient. When they get busy, questions can sometimes take too long to get answered.
They have little emotional investment in the process.
Deadlines and opening dates are the only thing that matters. I have seen corporate firms do full redesigns to placate local building officials without blinking an eye.
They are not afraid to spend money to get things done. The fast-track construction concept came about just for big box retail.
They are not used to dealing in your area. Try not to suggest, “we do it this way around here.”
Junior people handle stuff first. Get used to clearly explaining an issue so the next person up the ladder has all pertinent data.
The Process
The biggest factor in commercial work is the time from land acquisition to opening day. Pay and bonuses for employees involved are measured by expediency of their work. A month delay for a big retailer translated into hundreds of thousands of dollars in lost revenue. They still have a bottom line. Quick decisions to problems are important to keep in mind.
Over 15 years ago, I wrote an article for a magazine that included the thought, “all the good dirt is gone.” The nice flat building sites with well compacted soil and no garbage were all developed and all that is left is the stuff that is expensive and difficult to work with. The land is acquired by the company and the process begins. For this part, both commercial and private work follow the same course.
The selection of an engineering firm takes one of two roads. The company has a nationally registered firm, meaning they have people with a license in each state they work in. The other track is to contact a local firm that has experience in the area to get things going. I have not seen much difference in the choice. An advantage of a local firm is that if you get the job, communication could be smoother.
Next, a survey of the property is performed and submitted to the engineer and owner. These will be ALTA Surveys. This means they conform to the American Land Title Association guidelines that follow strict standards for real estate transactions. I remember a job involving a McDonald’s restaurant in Las Vegas that had three surveys performed to verify the plot. The land was priced by the square foot, so every little bit made a difference for all involved.
The survey is just 2D and clearly outlines the property boundary. At the same time, a topography map is usually made to provide the engineer with a starting point.
Site Specifics
We all know what a Wal-Mart or Home Depot looks like. When it comes to the area surrounding the building, this is where things must conform to the site purchased. The process being backwards, at least to us civil types. The footprint of the building is decided. How big a structure needs to be built to supply the anticipated traffic. From there, the civil engineer takes the job. There are fixed and fluid variables that enter into the site design equation, and many of them are decided by local codes.
Drainage needs to be sorted first. Knowing how big the building is, how much of the project do we need to dedicate to drainage? Most local codes will let you work in cubic feet of storage, meaning deeper basins that take up less area. Some require a percentage of the site have allocated green space, which also can be retention basins.
Number of parking spaces may be called out by ordinances. Handicap spaces are also controlled that way. This is the reason you may see a lot of accessible spaces in some parking areas and not many in others. Local codes adjust that. The only requirement is they do not allow less density than the ADA guidelines outline.
Access is next. We would love every entry to have a nice long decel lane, wide access driveways, and plenty of entrances and exits. The site will restrict this as well as the roads they enter.
The owner and engineers will need to look at the aesthetics and curb appeal of the project. Nobody wants to enter an unwelcoming site. Green space, trees, and easy access are all key.
There is no such thing as a great parking lot design. All ideas have drawbacks. Make something easy to navigate and somebody will find a way to gum things up. Useable area has the biggest impact on one way or two-way lot lanes, nothing else.
With these less than desirable plans in your hands, you bid the job. The hard bid was won, and it is time to work. I have seen many a small to medium contractor do a bang-up job for an owner and get asked to do more on a negotiated basis. Keep that in mind when you look at this type of work.
My best advice is to submit your concerns right after being rewarded the job. You already have the list of concerns that was made during the takeoff, estimate, and bid where contradictions and confusing details were presented in the plans so this should be easy. Addressing concerns at the start will accomplish two goals, it shows that you’ve studied the plans well and gives you the chance to bail if you do not like their answers.
Change orders are normal. Do not hesitate to fully explain the problem and solution. Your submission will most likely pass through two or three people before it gets approved.
Fully explain the issue requiring the change order.
Propose a fix and the cost associated. Remember, never ask a question without providing your own best answer.
Make your submittal stand on its own. In other words, if I read your change request and have any questions, you did not do your job well enough.
Site selection, design and construction are all handled by different people. Seldom does one person follow a project through. Make sure everything is written down. Communicate with all stakeholders so that there is no misunderstanding when things get handed off.
