Non-destructive detection method for pile bottom karst

Abstract

The invention discloses a non-destructive detection method for pile bottom karst. In the method, according to the spherical wave reflection principle, a cruciform section is arranged on the surface of a pile bottom rock stratum to detect the reflection information of inner karst with a certain depth; and the development state and the property of the pile bottom karst are judged by a quantitative experience formula via the time-domain and frequency-domain recognition. The method is used for carrying out full-profile scanning on the pile bottom rock stratum, forecasts the distribution situationof the pile bottom karst, comprehensively judges the integrity degree of the pile bottom rock stratum and forecasts the engineering construction in advance. Compared with the commonly-used drilled core method and CT (computed tomography) technology, the non-destructive detection method is more economical, has higher efficiency and avoids the defects that the pile bottom karst can not be completely known with the drilled core method and the CT method is uneconomical to detect the pile bottom karst.

Description

technical field [0001] The invention relates to a non-destructive detection method for pile bottom karst, which belongs to the technical field of geotechnical engineering investigation. Background technique [0002] Pile bottom karst detection is a survey technology that uses direct (drilling method) or indirect method (geophysical prospecting method) to detect the karst distribution characteristics within a certain range of pile bottom bedrock bearing layer. The purpose of pile bottom karst detection is to discover possible pile bottom karst through detection, and then take measures to avoid the damage caused by karst to the pile foundation (reduction of bearing capacity and stability), which is a necessary link for the hole formation of cast-in-place piles in karst-developed areas. The commonly used pile bottom karst detection methods in the past mainly include core drilling method and CT technology. Both methods require destructive drilling of the pile bottom rock formati...

AI Technical Summary

Problems solved by technology

Due to the randomness of the distribution of karst at the bottom of the pile, the core drilling method can only find the distribution of karst directly facing the borehole, and cannot accurately judge the scale of karst, and the possibility of underreporting karst is also very high. The detection has certain limitations, and at the same time, the cost is high and the construction period is long

Multi-section CT technology can accurately locate the karst at the bottom of the pile, but this method needs to construct multiple pairs of boreholes on the side of the pile at the same time to test, so the cost is expensive and the construction period is long, and it is usually difficult to implement when the number of piles is large

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