Excavations like trenches are a familiar site on new construction, demolition, and renovation sites. Before engineers can design an excavation and shoring system project, they must determine the soil type. Soils are classified based on how cohesive they are. Stable soils aren’t as high-risk as unstable soils. However, for safety’s sake, it should be assumed that any soil type has the potential to cause hazards like cave-ins. Arrange for shoring rentals as needed.
Stable rock can be excavated with walls of 90 degrees, and it will remain intact. Stable rock can refer to any natural, solid mineral material. Some examples include deposits of granite and sandstone.
Class A, B, and C Soils
Any material that isn’t solid, stable rock can be classified as an A, B, or C soil. Type A soils are the most cohesive materials. According to OSHA, type A soils have an unconfined compressive strength of 1.5 tons per square foot (tsf). Two examples of type A soils include clay and clay loam. Soil cannot be classified as type A if any of the following conditions apply:
- It’s fissured
- It’s been subjected to any kind of vibrations
- It’s previously been disturbed
- It has seeping water
- It’s part of a sloped, layered system
Type B soils are less cohesive than type A soils. They have an unconfined compressive strength between 0.5 tsf and 1.5 tsf. Examples of type B materials include angular gravel, silt, and silt loam. Type C soils are the least stable type. These weak soils have an unconfined compressive strength of 0.5 tsf or less.
Soil Type Tests
There are a few tests that engineers can use to assess the soil type of an excavation site. Engineers often use pocket penetrometers, which are small measuring devices. The shaft of the device is pushed into the soil. The device then provides the tsf measurement of the soil. Other tests include:
- Plasticity test
- Dry strength test
- Thumb penetration test
The engineers at Scaffold Resource are highly trained and experienced in all types of safety issues regarding excavations and shoring systems. If you’re anticipating the need for shoring erection at a site near Washington, D.C., get in touch with us right away to discuss your project’s needs. You can reach a friendly staff member at (301) 924-7223.
Every year in the U.S., construction workers sustain serious injuries and some lose their lives due to falls from elevated work positions. Even one death or injury is one too many. Before a worker is permitted to access the scaffolding, he or she must be thoroughly trained in the dos and don’ts of scaffolding safety.
Do undergo appropriate training and retraining.
A qualified person must conduct training sessions for each worker who will use scaffolding. During training, workers must learn how to properly identify hazards, including falls, falling objects, and electrocution hazards. Workers must also be trained on the proper use of scaffolding, including the structure’s load capacities and the handling of materials. Workers should undergo retraining if any of the following conditions apply:
- The supervisor feels the worker wasn’t adequately trained initially
- The type of scaffold, fall protection, or falling object protection systems change
- There are changes at the jobsite
Don’t use uninspected scaffolding.
A competent person must inspect the tube and clamp scaffolding before each day’s work can begin. The scaffolding should also be inspected after it is moved or modified in any way. Workers who are unsure about the status of the structure should check with a supervisor before using it.
Do use personal protective equipment (PPE).
Workers who are using scaffolding must always use appropriate PPE. This includes a hard hat and non-skid work boots. Workers must also use fall protection systems as appropriate.
Don’t make unapproved modifications to the work surface.
If the work platform isn’t high enough to reach a work area, don’t use a ladder or stand on a box to reach the work area. This increases the risk of a fall. Instead, alert the supervisor that the scaffold platform needs to be raised. If stilts are used, the guardrails should be raised to a height that’s equal to the height of the stilts.
Partner with a company that makes safety a top priority: Scaffold Resource. We provide a full range of scaffolding rentals and support services in Washington, D.C., and we have an excellent track record to prove our commitment to safety. Call (301) 924-7223 to discuss our available construction scaffold rentals.
Excavations are inherently dangerous activities that require careful planning to mitigate the risks. Every excavation site needs competent workers who understand the ins and outs of shoring systems and the proper sloping of trenches. For a closer look at some of the shoring requirements, watch the accompanying video. It discusses the proper installation of trench jacks and upper cross braces, and it explains how many sets of stringers and cross braces are required, based on the depth of the trench. The video also examines the conditions in which plywood can be substituted for uprights.
For safe and compliant shoring systems in Washington, D.C., your company can turn to Scaffold Resource. Call (301) 924-7223 to let us know about your shoring erection needs.
The Bethel African Methodist Episcopal Church (Bethel AME) in Baltimore has operated continuously since 1785. It’s Maryland’s oldest independent, continuously operating African-American church. In the summer of 2009, a lightning strike caused considerable damage to the church, forcing the congregation to temporarily hold services elsewhere. Scaffold Resource was honored to spearhead the restoration efforts.
The Scaffold Resource team used needle beams to create a structurally sound base that enabled scaffolding access about 80 feet in elevation. In order to transport repair materials up to varying elevations, we installed a material-only lift. Keeping in mind the congregation’s need to gather, Scaffold Resource installed overhead protection to enable safe access and egress points. Our team also installed a temporary stair tower and trash chute to support the functional operation of the church.
If your organization requires construction scaffolding in Washington, D.C., you can call our office at (301) 924-7223. Scaffold Resource looks forward to helping you bring your project to fruition.