Construction method for pit well of strong weathered rock foundation rich in low-pressure-bearing fissure water

Abstract

The invention relates to a construction method for a pit well of a strong weathered rock foundation rich in low-pressure-bearing fissure water. The construction method comprises the following steps that (1) a water collecting pit is chiseled in the bottom of the pit well; a flow guide hole is drilled in the side wall of the pit well; a flow guide pipe is plugged into the flow guide hole; a circle of collecting pipes are horizontally arranged on the peripheral side wall of the pit well and are in communication with the flow guide pipes; a drainage pipe is connected to the lowest part of the collecting pipe and extends to the water collecting pit; a water pump is arranged at the bottom of the water collecting pit; pit bottom concrete is poured; a side template supporting cushion block is anchored on the side wall of the pit well; and side formworks corresponding to the side walls of the pit well are installed on the inner sides of the side formwork supporting cushion blocks, scaffold pipes are arranged on the inner sides of the side formworks to outwards support the side formworks, concrete is poured between the side formworks and a rock stratum, the collecting pipe, the drainage pipe and a water pump drainage pipe are poured into the concrete, and the surface of the concrete is cleaned after vibrating and compacting. The constructed pit well is high in strength and good in flatness; and waterproof construction is facilitated, after the water content of the concrete meets the requirement, the bottom plate can be constructed for waterproofing.

Description

technical field [0001] The invention relates to a construction technology of strong weathered rock foundation, in particular to a construction method for pit wells of strong weathered rock foundation rich in low pressure fissure water. Background technique [0002] When constructing an elevator shaft or sump pit, if the excavation of the foundation pit encounters a strong weathered rock foundation, the shape of the elevator shaft and sump pit cannot be dug out with an excavator like ordinary earthwork, but it needs to be excavated by a breaker Cut out the shape of an elevator shaft or sump step by step. The bottom of the pit and the side walls are uneven, and the cushion layer cannot be directly constructed. In the prior art, the construction of the bottom cushion is generally completed first, and the side wall is constructed using the process of masonry + backfilling graded sand and gravel, and the slope of the side wall is built by masonry, and then plastered with 1:2.5 c...

AI Technical Summary

Problems solved by technology

Due to the influence of fissure water in the construction of elevator shaft and sump side wall cushion, no matter whether masonry + backfilling graded sand or concrete is used, it is difficult to construct smoothly. Even if the construction is completed, the quality of the cushion is not easy to guarantee , due to the impact of crack water, the moisture content of the cushion is too high, which will affect the later waterproof construction, and then affect the overall construction period

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