Method for constructing anchor cable on sand layer

Abstract

The invention discloses a method for constructing an anchor cable on a sand layer, and belongs to the technical field of supporting of foundation pits. According to the technical point, the method comprises the following steps of: (1) drilling a hole in a foundation on the rear side of a constructed foundation pit supporting structure according to design requirements; (2) cleaning a drilled hole wall; (3) putting the anchor cable into the cleaned hole; (4) filling cement mortar or cement slurry into the hole to fix the anchor cable; and (5) tensioning to lock the anchor cable when the cement mortar or the cement slurry reaches designed intensity. The method is characterized by comprising the following steps of: in the hole drilling process in the step (1), drilling by using a double-layer structure, namely drilling by arranging an outer sleeve at the periphery of a pivoted lever of a drilling machine when the drilled hole is positioned on a sand layer rich in water, and keeping the outer sleeve in the sand layer rich in the water without extraction after hole drilling construction is finished. The method for constructing the anchor cable on the sand layer is easy and convenient to operate and is used for constructing the anchor cable in the foundation pit supporting process; and by the method, sand can be effectively prevented from overflowing out of the sand layer rich in the water.

Description

technical field [0001] The invention relates to a construction method for foundation pit support, in particular to a sand layer anchor cable construction method. Background technique [0002] The construction method of prestressed anchor cables has been widely used in the support of foundation pits. The principle is to use the reaction force provided by the anchor cables and the prestress applied to the supported structure to resist the earth pressure during excavation of the foundation pit. And water pressure, to achieve the purpose of controlling the deformation of the envelope structure. During anchor cable construction, firstly use a drilling rig to drill holes according to the design requirements, then put steel strands and grouting pipes in the drilled holes, and finally pour cement mortar or cement slurry to complete the anchor cable construction. When the cement mortar or cement slurry reaches the design strength, the supporting structure is prestressed and anchored...

AI Technical Summary

Problems solved by technology

However, in the existing anchor cable construction method, when the foundation pit reaches a certain depth and encounters a water-rich sand layer, after the anchor cable is opened, due to the high water pressure in the sand layer, the gap between the casing and the pre-embedded conduit during drilling The gap is not blocked, and under the action of water pressure, the sand particles gushes out together with the groundwater, which may cause the anchor cable to fail to be constructed smoothly, or cause the ground outside the foundation pit to subside, threaten the safety of the building, and cause serious quality accidents

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