TRENCH SHORING

OSHA Standard 29 CFR Part 1926 Subpart P is the part of the Federal Standard that deals with excavations. Under 1926.652 “Requirements For Protective Systems” it is stated: “(1) each employee in an excavation shall be protected from cave-ins by an adequate protective system designed in accordance with paragraph (b) or (ac) of this section except when (i) Excavations are made entirely in stable rock; or (ii) Excavations are less than 5 feet (1.52m) in depth and examination of the ground by a competent person provides no indication of a potential cave in”.

To summarize, if you create an excavation that is not in solid rock and is more than 5 feet deep, you are required to protect workers from potential cave ins. To achieve the necessary level of protection for your workers you can SLOPE, SHIELD or SHORE:
• SLOPING – the method by which the walls of the trench are cut back at a ratio to the depth of the trench to insure the trench walls cannot collapse into the trench.
• SHIELDING – the method by which a solid structure is placed inside the trench to “shield” a worker in the event of a trench wall cave in.
• SHORING – the method by which devices re-insert energy back into the trench walls to create a positive physical restraint to prevent trench wall cave in.

All three of these methods have their pros and cons. No one single method will address all of the many possible combinations of trenching conditions. The one common thread of these three methods is the need for the “system of choice” to be designed by a Registered Professional Engineer. To have a Registered Professional Engineer design a shoring plan is time consuming and expensive. The obvious answer to this problem is to use a pre-approved trench shoring method when ever possible. This is where we can help you. We have many pre-approved trench shoring devices to address your trench excavation safety needs. Each device will be delivered with a Tabulated Data Sheet that specifies the engineered rating of that specific device.

Top View

Hydraulic shoring is a system of engineered devices that are designed to prevent cave-ins in all but unstable soil conditions, by supporting the side walls of the trench through the use of hydraulic pressure. Hydraulic shores are pressurized utilizing a hand pump that pumps a mixture of water and shoring fluid into the hydraulic shoring device.

Vertical Hydraulic Shores or “trench jacks” (as they are sometimes refereed to) are a combination of hydraulic cylinders connected to rails that are ideal for use in primarily stable soil conditions. Some of the major benefits of vertical shores are that they are quick, safe and simple to use. They are also designed to be installed and removed from the top of the trench 100% of the time. They can be used for spot bracing for repair situations, or can be used for production trenching. A wide assortment of sizes in both the cylinders and rails allows you great flexibility in addressing your trench shoring needs.

Vertical Shore Features
• Lightweight aluminum alloy construction for both exceptional durability, and easy portability
• Cylinders feature over-sleeve protection and safety bleed-off port
• Molded plastic pump bucket delivers 50% more volume per stroke than comparable steel pump bucket • All vertical shores are certified by a registered professional engineer to meet OSHA standards
• Complete manufacturer’s tabulated data, and installation/removal procedures are provided

Aluminum hydraulic shields consist of lightweight, aluminum side walls, coupled with heavy-duty hydraulic struts. The strut contains a hydraulic cylinder and return spring, and is protected by steel box tubing. A uniquely designed manifold allows the user to precisely control the flow of fluid to each cylinder, while safely outside the trench. This makes hydraulic shields ideal for irregular size excavations. The shields may be used in a hydraulic mode, providing pressure on the sides of the trench, or in a static mode – much like a standard trench shield. Because of their lightweight and easy assembly, these shields can be handled easily by rubber-tired backhoes. They are ideal for municipal maintenance or repair projects, utility or cable work, and light to moderate duty general underground contracting.

HYDRAULIC SHIELD FEATURES
• Lightweight aluminum sheeting side walls with sturdy lifting eyes
• Heavy duty skid plates and sheeting caps reinforce top and bottom of sheeting side walls •Heavy duty strut protects cylinder, and features end loading capability for 3 and 4 sided use
• Multiple pinning locations in strut permit a wide range of settings when the shield is used in the static mode
• Fold down, all steel manifold cover protects manifold when shield is in use, yet permits quick access to hydraulic hook-ups
• All hydraulic shields are certified by a registered professional engineer to meet OSHA standards

Our molded plastic hydraulic shoring pumps are lightweight, stable and durable. An improved pump design delivers 50% more shoring fluid per stroke than comparable steel pump buckets. The 5 gallon capacity,12 foot long hose and quick connect fitting makes the shoring pump convenient and user friendly.

***CAUTION***
ONLY shoring hydraulic fluid concentrate mixed with water is acceptable for use with hydraulic shores and hand pumps. Any other type of fluid, such as hydraulic oil, brake fluid, engine oil, etc. will damage the aluminum components as well as the rubber seals.

The Lite-Shield 24 Series offers you a wide choice of panel lengths, from 3 to 12 feet. The lightweight 24-inch panels can be transported easily, even in a pick up. The system assembles in just minutes. Tongue-in-groove panels are easily aligned, and mechanical screw-jack struts provide fast, variable adjustment. For maximum versatility, the system can be used as a 2, 3 or 4 sided configuration.

• Strong yet lightweight 6061-T6 aluminum construction
• 2-inch wall thickness
• Foam filling as an option
• Certified by a professional engineer to meet OSHA Test standards
• Easily transported, even in a pickup truck
• Easily assembled/disassembled by 2 men

The design of this trench shield series utilizes the latest developments in steel strength, engineering, know-how, and field experience. And, of course, they continue to maintain the high standard of workmanship that contractors have come to rely on from G.M.E. for over three decades. Front and rear spreader arrangements allow for high pipe clearance at both ends of the trench shield (64 inches of clearance with an 8 foot high shield).

"A" SERIES trench shield features:
• Non-rigid design
• Heavy duty cutting edge (on shields with knife edge)
• High tensile steel throughout
• Unitized thru-wall collar assemblies
• Honey-comb inner structure
• Slot welding • Standard 4 point lifting lugs (recessed)
• All certified by a licensed Professional Engineer to meet OSHA standards
• Utilizes A Series loose spreader system
• Utilizes 8" schedule 80 spreader pipes with 2" diameter pin
• Built-on stacking lugs

A manhole box is a must for almost any new manhole installation or manhole repair. The four sided square configuration surrounds the pit while providing the much needed inside clearance. A major advantage of a manhole box, as compared to a standard trench shield, is the reduction in the amount of excavation and restoration needed.

For your convenience, we carry two different styles of the manhole shield. The first of these is a fixed four sided configuration. It is fixed 8'x8'x8' box. All you need to do is pick it up and drop it in. No assembly required. There are removable doors on all four sides to allow for pipe clearance. The second type utilizes the loose spreader pipe style on two sides. This affords you some adjustability on two of the four sides, for those odd size manholes. The spreader pipes are set to provide a 45 inch pipe clearance.