Shoring Systems Checklist for Urban Construction
- Joe Lazzaretti
- Jul 21
- 13 min read
Updated: Sep 2
Urban construction demands precise planning for shoring systems to ensure safety and structural stability. Tight spaces, underground utilities, and proximity to buildings add complexity. Here's a quick guide to help you manage shoring effectively:
- Site Assessment: Measure space, check equipment access, and map underground utilities to avoid delays and hazards.
- Load Calculations: Factor in dead, live, and environmental loads to design a safe system.
- System Selection: Choose from methods like soldier piles, sheet piling, or soil nailing based on site conditions.
- Permits & Access: Secure property agreements and comply with city codes early to prevent project delays.
- Safety Compliance: Follow OSHA rules, conduct daily inspections, and train workers on hazard prevention.
Urban shoring isn’t just about supporting excavations - it’s about protecting workers, infrastructure, and project timelines. Proper planning and daily oversight are key to success.
What Are The Different Excavation Shoring Systems? - Civil Engineering Explained
Site Assessment and Planning
Before diving into construction, it's crucial to evaluate the site thoroughly to choose the right shoring system. A solid understanding of site conditions can help avoid costly delays and safety concerns, laying the groundwork for proper system selection, installation, and ongoing safety measures.
Check Space Limits and Equipment Access
Urban construction sites come with unique challenges, especially when it comes to limited space and maneuvering equipment around existing structures. Accurate measurements and detailed planning are essential. Start by gathering data on the site’s perimeter, topography, soil type, moisture levels, and accessibility. Using modern surveying tools can ensure precise measurements and help determine whether equipment can move freely on-site [2].
Physical constraints like existing land features, access points, and nearby buildings also play a big role. Plan for traffic flow, including vehicle entrances and exits, pedestrian zones, gate placements, and parking for the crew [3].
Material storage is another key consideration. Look for areas that are large enough to accommodate shoring materials, provide weather protection, allow easy access for delivery trucks, and ensure security for expensive components. Keep in mind that shoring materials often arrive in large sections, so ground preparation and access roads are essential [3].
For example, one urban construction project faced restrictions after the initial concrete pour. While the first pour allowed full concrete loads, subsequent pours were limited to 8-yard loads due to space constraints [3].
Once space and access are planned, the next step is to map underground utilities to prevent potential risks.
Map Underground Utilities and Infrastructure
Mapping underground utilities is essential to avoid accidents, delays, and financial losses during shoring projects, especially in urban areas. Dense networks of gas lines, communication cables, sewer systems, and water pipes often create challenges. In the UK alone, accidental strikes on underground utilities cause an estimated loss of £1.2 billion annually [6].
A thorough survey helps identify potential hazards early, allowing for effective mitigation. Combine multiple tools for comprehensive utility mapping. Electromagnetic locators are ideal for detecting metal utilities, while ground-penetrating radar (GPR) works well for various underground structures. In sandy or waterlogged soil, acoustic methods can be more effective. For the most precise results, potholing offers a hands-on approach to locate utilities accurately [4].
Start this process during the pre-design phase to guide site decisions. Use data from existing maps, GPR surveys, and other sources to create detailed utility maps that highlight potential conflicts [4][5].
Jim Anspach, P.G., Dist.M.ASCE, NAC, underscores the importance of thoughtful planning:
"Why do I need the information? What's the return on investment of that information? How reliable does it need to be for this specific task?" [4]
Subsurface Utility Engineering (SUE) provides a framework for determining the accuracy level of utility data. Quality Level A offers the highest precision through techniques like vacuum excavation, while Quality Level D relies on existing utility records and is less definitive [4].
With utility mapping complete, the focus shifts to securing property access and obtaining the necessary permits.
Secure Property Access and Permits
In urban construction, gaining access to neighboring properties is often unavoidable. Early access agreements are critical for smooth shoring installation [8]. Securing building permits without delays depends on these agreements, so it’s important to start early. Reach out to property owners directly to get their consent for site access, and negotiate terms that cover usage areas, restrictions, duration, and any associated fees [7].
Formalize these agreements in writing, outlining the rights and responsibilities of both parties. Include clauses for termination and dispute resolution, such as arbitration or mediation, to address potential conflicts [7]. Additionally, assess potential risks and ensure adequate insurance coverage to protect against damages during construction [7].
If property owners are unwilling to grant access voluntarily, developers can seek legal remedies. Under RPAPL §881, a court can grant a license to access neighboring properties. A recent case set limits on licensing fees and required timely project commencement [8].
Legal counsel can help ensure compliance with local laws and safeguard your rights during the process. Communicating with nearby residents is also important to minimize disruptions and maintain good relationships with the community [7].
Consider using permit expediting services to streamline the process. These services can help ensure that your application is accurate and complete, reducing delays. Before starting shoring installation, double-check compliance with local building codes and verify that all required permits are in place [2]. A comprehensive site survey report, complete with maps, charts, and photos, can strengthen your permit application [2].
Load and Structural Requirements
Accurately calculating loads is essential to prevent structural failures and ensure worker safety. This is especially important in urban construction, where tight tolerances and nearby infrastructure demand precise load analysis. A well-executed load analysis ensures that your shoring system can handle soil pressure, construction loads, and seismic forces without compromising safety.
Calculate Expected Loads
Shoring systems must account for three primary types of loads: dead, live, and environmental loads. Here's a breakdown of each:
- Dead loads: These are permanent forces from structural elements such as beams, columns, and walls.
- Live loads: Temporary forces caused by people, equipment, and construction materials.
- Environmental loads: Forces from natural phenomena like wind and seismic activity [9].
For example, a 10-ft × 33-ft concrete wall with an 8-inch thickness has a volume of approximately 212 ft³ and weighs about 31,800 pounds [9]. Similarly, a floor area of 1,076 ft² with a live load of 62 lb/ft² results in a total load of roughly 66,712 pounds [9].
Wind loads also play a role. A wind speed of 67 mph generates a pressure of about 11.5 lb/ft², which, depending on the exposed surface area, could translate to a total wind load of around 3,720 pounds [9]. In areas prone to earthquakes, seismic loads become critical and must align with local building codes.
Urban construction often requires additional considerations. For instance, Caltrans specifies a minimum lateral construction surcharge of 72 lb/ft² applied to shoring systems up to a depth of 10 feet. Alternatively, its traffic surcharge applies a uniform lateral pressure of 100 lb/ft² to the computed depth of the shoring system [14].
To determine the total load, combine all these factors. For instance, adding a dead load of 31,800 pounds, a live load of 66,712 pounds, and a wind load of 3,720 pounds results in a total load of 102,232 pounds [9]. Ensure you apply appropriate safety factors to account for worst-case scenarios.
Once you've established these load values, align your shoring system with the permanent structural design for seamless integration.
Match System to Structural Design
A Specialty Structural Engineer (SSE) typically handles the design of shoring systems for temporary loads. This responsibility often falls outside the scope of the Registered Design Professional (RDP), as shoring systems are not part of the permanent structural design [11].
After quantifying the loads, the SSE ensures the shoring system accommodates temporary conditions while aligning with the final structure. This process involves evaluating several factors, including:
- Temporary construction loads
- The project's operational needs during construction
- The selection of appropriate shoring types
- The capacity of existing structures to handle altered load paths
- Construction sequences and methods preferred by the contractor [11]
Shoring temporarily alters load paths, so the SSE must assess whether existing structural elements can handle these changes [11]. For flexible walls, AASHTO recommends using a 2:1 (vertical:horizontal) method to estimate increases in vertical stress with depth. By multiplying this stress increase by the active earth pressure coefficient (Ka), you can estimate the corresponding lateral pressure [14].
Modern structural analysis tools, such as ASDIP Foundation, SkyCiv Load Generator, STAAD-Pro, RISA, SAP2000, and ETABS, simplify these calculations [12] [13] [15].
"It's the best engineering software, especially ASDIP FOUNDATION. I've tried other software but ASDIP overcomes all of them. The detailed calculation on the output, the user-friendly GUI, ASDIP is the best." - Ruel Paler, PE, R2P Construction Services [12]
In densely populated areas, environmental factors and city regulations often demand complex shoring designs. These designs must address challenges such as below-grade infrastructure, sensitive utilities, and high groundwater levels [10]. One effective solution is soil-cement mixing (SMX), which creates continuous shoring walls that support excavations while serving as hydraulic and contaminant barriers [10].
When selecting shoring types - vertical, horizontal, raking, or flying - ensure proper spacing to evenly distribute loads. Verify all calculations thoroughly and make adjustments as needed to guarantee the system's reliability and safety before installation begins [9].
System Selection and Installation
After completing a thorough site assessment, the next step in urban construction is choosing and installing the right shoring system. Factors like soil type, excavation depth, nearby structures, water table levels, project timeline, budget, and site limitations all play a role in this decision. Urban projects also bring unique challenges, such as limited space, noise restrictions, and the need for quick installation [18].
Choose the Right Shoring Method
The first step in selecting a shoring method is understanding the site’s conditions. For example, cohesive soils can support simpler systems, while granular soils might require hydraulic or beam-based solutions [16]. Excavations deeper than 25 feet often need engineered systems to ensure stability [16].
- Soldier Pile and Lagging Systems: Ideal for stable soils and projects with enough space for equipment. This method involves driving steel H-piles into the ground and placing timber or concrete lagging between them, making it flexible for irregular excavation shapes and utility access.
- Sheet Piling: Best for soft soils or areas with high groundwater levels, offering excellent water control.
- Secant Pile Walls: Provide strong structural support, suitable for deep excavations near sensitive structures, but require considerable installation space.
- Slide Rail Systems: Perfect for tight urban spaces or areas near existing buildings, as they need minimal space and allow for quick installation [20].
- Soil Nailing: Works well in restricted spaces and on slopes, using shotcrete and grouted anchors to secure vertical walls [19].
When deciding on a method, consider nearby structures, utilities, and space limitations for both installation and removal. It’s also crucial to comply with local building codes and safety standards [17]. Consulting with geotechnical engineers ensures the chosen system matches the site’s specific needs [16].
Follow Installation Steps
Proper installation is key to both the system’s performance and worker safety. Start by conducting a detailed site assessment, including soil testing, slope analysis, and utility mapping, to identify risks and determine the best approach [16].
- Preparation: Set up temporary supports and clear access paths [16].
- Installation Sequence: Always install shoring from the top down and remove it from the bottom up to maintain soil stability [22]. Follow manufacturer guidelines and check hydraulic components before use [16].
- Soil Nailing: Alternate between anchor drilling and applying shotcrete to secure the soil panels [19].
- Beam and Plate Systems: Ensure beams are driven to the correct depth for maximum stability [16].
Training workers on proper setup, use, and dismantling procedures is essential. For systems like cantilever piles or raker beams, precise alignment and bracing are critical for stability. Throughout the process, monitor the system’s performance and make adjustments as needed to maintain structural integrity [16].
Verify Proper Installation
Once the system is installed, verifying its stability and compliance is crucial. OSHA mandates daily inspections by a Competent Person, with re-inspections required if site conditions change [21]. Additionally, tabulated data and documentation, stamped by a Registered Professional Engineer, must be available on-site during installation [21].
Key verification steps include:
Hydraulic shoring systems should be inspected at least once per shift for leaks, broken parts, or other damage [22]. Regularly assess adjacent structures and soil conditions for signs of movement, settlement, or groundwater changes. Common issues like inadequate design, improper bracing, or unsecured connections require immediate correction [1]. Document findings in a detailed inspection report, noting any risks and recommended actions [1].
"Excavation shoring systems are not just tools but vital safeguards that uphold the integrity of construction projects, protect lives, and exemplify a commitment to safety and precision in every trench dug." – ICON Equipment [16]
Ongoing inspections are just as important. Look for shifting, leaks in hydraulic components, or warped materials, and keep detailed records to ensure the system remains reliable throughout the project.
Safety and Code Compliance
Ensuring safety and adhering to regulations isn't just about ticking boxes - it’s about protecting workers, the public, and your project from potential hazards, legal troubles, and delays. In urban construction, staying compliant means keeping thorough records and conducting regular inspections to confirm your shoring system meets all necessary codes throughout the project. It all starts with proper documentation.
Submit Required Documents
Before a shoring system can be approved, building officials need detailed documentation. This includes engineering drawings and shoring plans stamped by a Registered Professional Engineer for excavations deeper than 20 feet, as required by OSHA guidelines [26].
Geotechnical reports, outlining soil analyses and bearing capacity calculations, are equally critical. These reports ensure the chosen shoring system matches the site’s specific conditions, providing a foundation for safe and effective construction.
Once your paperwork is in order, the next step is strict adherence to OSHA regulations and local safety protocols.
Follow OSHA and Local Safety Rules
OSHA requires protective systems for trenches deeper than five feet and mandates professional engineering for those exceeding 20 feet [24][26]. Additionally, the General Duty Clause emphasizes maintaining a workplace free of serious, recognized hazards [25].
Key safety measures include installing fall protection around excavation perimeters and keeping a two-foot clearance from trench edges to prevent soil collapse caused by surcharge loads [29]. Workers must also have safe access to trenches - ladders, steps, or ramps should be placed within 25 feet of any employee working in excavations deeper than four feet [29].
Training programs are essential. Workers should be educated on hazard recognition, safe practices, and emergency procedures for excavation projects [26]. For trenches deeper than four feet, regular atmospheric testing is required, along with controls to ensure safe air quality [26].
"Shoring ensures safe excavations in urban construction by preventing soil collapse and protecting nearby structures." - BLOC Contractors [30]
Conduct Regular Inspections
Safety doesn’t stop with documentation or initial setup - it requires ongoing vigilance. Daily inspections are mandatory for all excavations, nearby areas, and protective systems [23][26]. These inspections should focus on identifying risks like potential cave-ins, protective system failures, hazardous atmospheres, and other dangerous conditions.
To maintain consistency, establish a routine that includes daily walkthroughs, weekly checks, and inspections tied to major project milestones [27]. Use standardized checklists tailored to your site’s unique conditions to document findings and address any issues promptly [27].
Encouraging open communication is just as important. Workers should feel comfortable reporting potential hazards without fear of retaliation [27]. Additionally, safety training for inspectors and workers ensures everyone stays up to date with current standards.
Finally, if an event like severe weather, nearby construction, or equipment impact raises concerns about the shoring system’s integrity, re-inspect immediately. Halt operations if there’s any doubt about safety, and consult qualified professionals before resuming work [26][28].
Summary
This checklist brings together essential steps, from site planning to system installation, ensuring each phase seamlessly supports the next. Urban shoring projects demand careful planning and strict adherence to safety standards to maintain structural stability while protecting workers and nearby infrastructure.
A thorough site assessment and detailed planning are the backbone of any successful shoring project. These steps help avoid costly delays and mitigate safety risks, especially in tight urban spaces with complex utility networks.
Selecting the right shoring system is critical for both project efficiency and worker safety. Whether it's timber shoring for shallow trenches or diaphragm walls for deep excavations, the choice must align with the site's specific conditions. Engineering calculations should account for urban-specific challenges, such as traffic loads and the impact of adjacent buildings. These factors ensure the system meets both operational needs and design requirements.
Safety compliance is a non-negotiable aspect throughout the project. Excavation shoring systems are essential safeguards, protecting lives and ensuring the structural integrity of the project. With trench accidents posing serious risks - considering that a single cubic yard of soil can weigh around 3,000 pounds - strict safety measures are crucial. OSHA mandates protective systems for trenches deeper than 5 feet, and daily inspections by a qualified professional help identify hazards before they escalate [31].
In urban construction, shoring decisions extend beyond the immediate site. They impact neighboring buildings, underground utilities, and public safety. Regular monitoring, meticulous documentation, and clear communication with all stakeholders are key to ensuring a successful and safe project outcome.
FAQs
What are the best ways to locate underground utilities during urban construction projects?
Accurately locating underground utilities is a crucial step in urban construction projects. It ensures safety, prevents accidents, and avoids expensive delays. Some of the most reliable tools for this task include:
- Ground-penetrating radar (GPR): This technology uses radar pulses to detect and map subsurface objects, making it ideal for identifying buried utilities.
- Electromagnetic locators: These devices are specifically designed to locate underground cables and pipes with precision.
- GPS-based mapping tools: These tools create detailed digital layouts of utility networks, offering a clear and accurate view of underground infrastructure.
By combining these technologies, construction teams can visualize underground systems in real time, allowing for smarter planning and significantly lowering the chances of accidental damage during excavation.
How can I choose the right shoring system for a construction site with limited space and challenging soil conditions?
Choosing the right shoring system for a site with limited space and challenging soil conditions involves weighing several important factors. Start by evaluating the soil's stability, the depth of the excavation, and the space available for equipment and materials. In tight spaces with unstable soils, systems like hydraulic shoring or soil nailing often work well, as they offer reliable support without requiring much room.
For more complicated scenarios, consider options like sheet piles or diaphragm walls, which are versatile enough to handle various soil conditions and project demands. To ensure the system aligns with safety requirements and local regulations while maintaining structural integrity, it's essential to consult with a professional and carry out a detailed site assessment.
What are the key steps to comply with OSHA regulations when installing and maintaining shoring systems?
To meet OSHA standards during shoring system installation and maintenance, it's important to follow the guidelines specified in 29 CFR Part 1926, Subpart P. This includes using appropriate support systems like hydraulic or timber shoring and making sure all components are securely connected. For trenches over 5 feet deep, protective systems are required to prevent cave-ins.
OSHA also requires safe access for trenches 4 feet or deeper. This means providing ladders, steps, or ramps, with an exit point available within 25 feet of workers. Moreover, a competent person must oversee the installation and removal of shoring systems. Their role is to ensure safety, monitor soil conditions, and address potential risks.
By following these guidelines, you can maintain worker safety and stay compliant with OSHA regulations in urban construction projects.
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