The main members of the shoring system must be placed in such a way that it will provide as much direct resistance as possible to the load to be carried. While calculating the load is extremely difficult, there is a need to assume that each shore is capable of extreme conditions of loading. This is despite the fact that the walling of the structure may provide a certain degree of resistance to the loads.
An important element of shoring is the safety of workers. The basic idea is restoring the equilibrium of the horizontal forces that are acting on the trench walls, for instance. The main function of the shoring system is actually bearing against the exposed side walls of trench so that the horizontal forces acting on the trench walls will be balanced. Shores are usually under compression when utilized in supporting trench walls in a typical trench shoring design problem.
There are specific parameters affecting the shoring material choice and design that also ensures the workers' safety. These parameters include compressive force of each shore, distance between two consecutive points of shoring support, shear strength values of the soil, and level of ground water table.
Yet another area to focus on in designing and installing the shoring system with safety in mind is the requirement for adequate working space in the trench. Installing the shoring system must be from top to bottom. Likewise, removing the shoring system must be from bottom to top. The key point here is that the workers installing or removing the shoring system must be always in the protected zone.
Perhaps, this is the reason why timber shoring is utilized in shoring systems to a great extent. Timbers are used due to its adaptability to be cut into shape and length. Timber shoring can be used independently wherein no additional components or combining it with other systems is not required. Aside from this, timbers have large salvage value even after dismantling the shores. Large cross-section timbers are used in preventing any chance of bending. Nevertheless, it is often wiser to use a €safe' size of timber instead of being sparing with it.
Further, the core members of the timber shoring system are cross braces, uprights, and wales (only when required). As already noted, the type of the soil should be determined first. Once the soil type is determined, the width and length of the trench should be determined then. When timbers are used for horizontal cross bracing, the size of the cross braces must be identified first since this will inform what is used in other parts of the system. Some of the other uses are vertical spacing of the cross braces, or shores and horizontal spacing of the uprights, or strongbacks.
An important element of shoring is the safety of workers. The basic idea is restoring the equilibrium of the horizontal forces that are acting on the trench walls, for instance. The main function of the shoring system is actually bearing against the exposed side walls of trench so that the horizontal forces acting on the trench walls will be balanced. Shores are usually under compression when utilized in supporting trench walls in a typical trench shoring design problem.
There are specific parameters affecting the shoring material choice and design that also ensures the workers' safety. These parameters include compressive force of each shore, distance between two consecutive points of shoring support, shear strength values of the soil, and level of ground water table.
Yet another area to focus on in designing and installing the shoring system with safety in mind is the requirement for adequate working space in the trench. Installing the shoring system must be from top to bottom. Likewise, removing the shoring system must be from bottom to top. The key point here is that the workers installing or removing the shoring system must be always in the protected zone.
Perhaps, this is the reason why timber shoring is utilized in shoring systems to a great extent. Timbers are used due to its adaptability to be cut into shape and length. Timber shoring can be used independently wherein no additional components or combining it with other systems is not required. Aside from this, timbers have large salvage value even after dismantling the shores. Large cross-section timbers are used in preventing any chance of bending. Nevertheless, it is often wiser to use a €safe' size of timber instead of being sparing with it.
Further, the core members of the timber shoring system are cross braces, uprights, and wales (only when required). As already noted, the type of the soil should be determined first. Once the soil type is determined, the width and length of the trench should be determined then. When timbers are used for horizontal cross bracing, the size of the cross braces must be identified first since this will inform what is used in other parts of the system. Some of the other uses are vertical spacing of the cross braces, or shores and horizontal spacing of the uprights, or strongbacks.
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