Excavation method for foundation pit drainage

Abstract

The invention discloses a foundation pit descending and drainage excavation structure and an application method, comprising the following steps: (1) measuring and setting out the range of the foundation pit to be excavated; (2) excavating the foundation pit to the Above the groundwater level, the cement-soil mixing piles constructed around the foundation pit overlap each other to form a water-stop curtain, and the water-stop curtain extends into the impermeable layer below the base level; (3) Continue to excavate the foundation pit to the base level by grading the slope in different areas. , excavation and drainage are carried out at the same time, and after the excavation is completed, a sprayed concrete surface is applied to the slope below the groundwater level. The invention isolates the groundwater outside the pit from the working surface in the pit during construction, and does not need to conduct well point dewatering during construction; meanwhile, it ensures that earthwork construction and dewatering and drainage are carried out simultaneously, greatly improving construction efficiency and ensuring construction quality.

Description

technical field [0001] The invention relates to the field of foundation pit engineering, and is actually an excavation method and structure for foundation pit drainage and drainage. Background technique [0002] With the rapid development of the construction industry and the emergence of high-rise buildings, most of the foundations are set below the groundwater level. If the groundwater problem is not solved properly, a large amount of groundwater will flow into the foundation pit and cause great trouble to the construction. This leads to the occurrence of foundation pit cracking and collapse and piping. In order to ensure the smooth progress of the project, the method of well point dewatering is usually used to lower the water level below the design base level before construction. But this method has the following disadvantages: [0003] 1. If the stratum has good permeability and the buried depth of the groundwater table is deep, and the well drilling and pumping is smoo...

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Problems solved by technology

[0004] 2. The efficiency of water drainage is low, and the construction period of high-rise buildings is generally longer, ranging from two to three years to several years, which will lead to an increase in the continuous cycle of water drainage work and unnecessary waste of resources

[0005] 3. Long-term extraction of groundwater will take away the surrounding sediment, which will increase the foundation gap of the building and reduce the bearing capacity of the foundation, resulting in the settlement of the surrounding buildings and deformation and cracking of the ground surface, causing serious consequences

[0006] 4. Long-term extraction of groundwater results in uneven distribution of water levels, causing groundwater outside buildings to be pumped out, resulting in waste of resources

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