Method for detecting seepage passage hidden trouble of waterproof curtain

Abstract

The invention relates to a method for detecting seepage passage hidden trouble of a waterproof curtain, comprising the following steps: vertically embedding a power supply electrode A in the central of a non-excavated foundation pit of a curtain, installing a power supply electrode B at the periphery of the foundation pit, wherein the power supply electrode B is driven underground; vertically drilling a probe hole outside of the curtain, placing a determination electrode M and a determination electrode N with fixed electrode distance, and connecting the determination electrodes M and N to an input of an electronic automatic compensator by lead, wherein the determination record point is the midpoint of the distance between M and N and the depth is x; determining natural potential differenceof delta V0(x) between the electrode M and the electrode N at the depth point x by the electronic automatic compensator; facilitating the reading of the determined potential difference of delta V0(x)to be zero by the natural potential compensation of the electronic automatic compensator; providing a current I to the electrodes A and B, and determining a potential difference of V1(x) at the two electrodes of M and N at the depth point x by the electronic automatic compensator and normalizing V1(x) by I; drawing the curves of delta V0(x) and V1(x) / I changed with the depth x on a depth coordinate graph; and if a plus-minus / minus-plus transition phenomenon appears on the curve of V1(x) / I, the zero value point between the plus value and the minus value corresponds to the existing position anddepth of the hidden trouble of the seepage.

Description

technical field [0001] The invention relates to a geophysical detection method, in particular to a detection method for locating hidden dangers in leakage channels of water-stop curtains. Background technique [0002] As the price of land becomes more and more expensive, making full use of underground space has become a trend in the development of urban buildings. The excavation and support of deep foundation pits are widely used in high-rise buildings and subway projects. Due to the constraints of construction equipment, surrounding environment, geology and hydrology, etc., water-stop curtains often cannot achieve complete lap joints. Therefore, it is difficult to fundamentally change the current situation of "ten pits and nine leaks" in foundation pits in sandy soil areas. During the excavation of foundation pits, leakage dangers often occur. If the quality of the water-stop curtain can be detected before the foundation pit is excavated after the water-stop curtain is for...

AI Technical Summary

Problems solved by technology

Before the excavation of the foundation pit, the better detection method recognized at home and abroad is to conduct a pumping test on the foundation pit inside the curtain to determine the location of the hidden danger of leakage, but this method is complicated in construction and detection, and is rarely used in construction sites

Due to the complex hydrogeological conditions of the water-stop curtain construction site, the water-stop curtain is deeply buried underground, and there are supporting piles, I-shaped piles and other construction facilities inside the curtain. The detection of hidden dangers is an internationally recognized problem, and there is no effective technology at home and abroad to achieve effective detection

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