The vertical members are composed of bored piles in anchored bored pile structures supported by variable levels and dimensions of horizontal supporting members composed of pre-stressed anchors and waling beams depending on factors such as the soil and groundwater conditions, environmental loads, deformation criterias, etc.
Initially vertical members of bored pile shoring system is constructed followed by step wise excavation and construction of anchors and beams according to the deisgn levels. Guide walls may be used to establish the correct positions of the bore piles, initially.
Bored piles can be constructed by using various capacity and sizes machinery and equipments, depending on factors such as; soil and groundwater conditions, diameter, capacity and the length of the pile. Bored piles are drilled by bentonite mud or casing depending on the ground conditions during the drilling, and length of the piles and the capacity of the equipment.
Bored piles are constructed in the following steps respectively:
- drilling
- placing of reinforcement
- concreting
After placing of the reinforcement concrete is placed using tremie pipes starting from the bottom of the pile to the surface.
Typically, the bored pile diameters are drilled by conventional drilling equipments to sizes between 65 cm to 150 cm.
Upon completion of the bored pile construction, bored piles are connected to each other with a head beam at the top level.
Head beam sizes may be variable depending on the design requirements and the diameter of the bored piles used. Prior to the construction of the head beam, the heads of the bored piles are cut and cleaned to the elevation specified in the design, and the reinforcement is arranged in order to connect the head beam reinforcement to pile reinforcement.
After completion of the head beam, excavation is performed in steps and the shoring system is formed parallel to the excavation, by constructing pre-stressed anchors and the waler beams. In cases where it is not possible to implement achors due to surrounding conditions, vertical bored pile members can be supported by supporting strut beams, depending on the size of excavation support system.
