Construction method for rapid water plugging and reinforcing near-pit wall of deep foundation pit in loose soil layer

Abstract

The invention discloses a construction method for rapid water plugging and reinforcing a near-pit wall of a deep foundation pit in a loose soil layer. The construction method comprises the following steps that firstly, the water gushing range of the inner wall of the foundation pit is measured, then a probing drill hole is constructed at a corresponding position to probe the width of a water gushing damage area and the maximum outer edge range of a water gushing affected area, then a compressive body is constructed, grouting reinforcing is conducted on the water gushing affected area firstly, then grouting reinforcing is conducted on the water gushing damaged area, and finally checking and supplementary grouting are conducted. According to the construction method, safety and stability of the foundation pit wall can be fully guaranteed, gushing water can further be effectively blocked, rapid grouting reinforcement is conducted on the water gushing area, and the hidden danger of water gushing is thoroughly eliminated.

Description

technical field [0001] The invention relates to the technical field of civil engineering, in particular to a construction method for rapid water blocking and reinforcement of a deep foundation pit in a loose soil layer near the pit wall. Background technique [0002] The deep foundation pits of high-rise buildings and urban tunnel foundation pits are generally designed in loose covering soil layers due to their shallow burial. When the underground diving or part of the confined water is exposed during construction, the problem of a large amount of concentrated water gushing is very prominent. A large amount of sediment is carried into the foundation pit during water gushing, which will cause the outer soil layer of the foundation pit wall to be washed away to form a cavity, and the risk of subsidence of the overlying stratum of the cavity is extremely high. The subsidence of the ground and the erosion of the gushing water will also cause serious instability such as cracking,...

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Problems solved by technology

Although the injected stones can slow down the water flow, the injected cement slurry still has the consequence of being diluted by the water flow

Moreover, the construction of large-diameter drilling itself is the damage to the surrounding soil layer of the foundation pit wall, and due to the limitation that the drilling holes cannot be connected and the diffusion range of stones in the stratum is small, it is difficult to cover the entire water gushing area with the method of injecting stones with large diameters. Especially for water gushing with high pressure and large flow rate, the above method is difficult to work. On the contrary, the best time to effectively control the gushing water will be lost due to construction, making it more difficult to block the gushing water, and even causing the foundation pit wall to become unstable and deformed. Even the consequences of collapse, resulting in engineering accidents

[0004] The existing method is to use polymer materials for grouting, but after the chemical reaction of the polymer materials, the volume of the reaction product will expand by a large multiple, and the expansion body will easily generate a large lateral pressure on the wall of the foundation pit. The wall of the foundation pit is extruded and deformed inward, and even cracked, bulged or even collapsed

There is also the use of micro-expansion quick-setting grout, but the grouting is not planned, the grouting sequence is not scientific and reasonable, and the concentrated water gushing is broken up, causing the wall of the foundation pit to expand the water gushing range, changing the concentrated water gushing into scattered water gushing, and making the water gushing disaster more serious. Complicated, it increases the difficulty of governance, consumes more money and time, and may also cause the consequences of failure to control water gushing

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