Karst soil cave exploring and positioning method

Abstract

The invention relates to the field of karst region soil cave collapse geological disasters, in particular to a karst soil cave exploring and positioning method. The method comprises the following steps that firstly, a working area required to be subjected to collapse exploring is selected; a spraying route is delimited for the selected area, and foaming agents are evenly sprayed till the content of the foaming agents in the earth surface covering layer soil body reaches the designed concentration; then whether bubbles are continuously generated on the earth surface or not are observed after raining, bubble generation points are marked, namely possible development positions of the karst soil cave, and finally the bubble generation points and adjacent areas are detected in detail by adoptinga conventional drilling or geophysical prospecting method to determine detailed characteristics of the soil cave. According to the technical scheme, the karst soil cave exploring and positioning method can achieve large-area, low-cost, easy-to-operate and accurate detection of the specific development position of the underground karst soil cave, can remarkably reduce the detection target area ofthe karst soil cave, and effectively solves the bottleneck problem of restricting the position of the soil cave in karst collapse monitoring and prevention at present.

Description

technical field [0001] The invention relates to the field of earth cave subsidence geological disasters in karst karst areas, in particular to a method for searching and positioning karst earth caves. Background technique [0002] Karst soil cave collapse is a common type of geological disaster in karst areas. According to incomplete statistics, there are more than 2,000 karst collapses on average in the country every year, causing direct economic losses of about 50 million yuan, threatening buildings (structures), public ( Railway transportation, cultivated land and other various infrastructures built on karst overburden and the safety of people's life and property. The main reason for karst collapse is that there are soil cavities within a certain depth (generally 3-10m) below the ground, and the inner diameter of the cavities generally ranges from 3-20m. When the soil on the top of the cavity cannot bear the relevant loads, it will collapse. , the direct manifestation of...

AI Technical Summary

Problems solved by technology

[0003] Due to the typical characteristics of karst soil caves, such as uncertain development location, strong underground concealment, and sudden disaster-causing process, it is difficult to carry out effective monitoring for them at present, and only conventional drilling and geophysical prospecting methods can be used to specifically detect them in advance. After the development location, size, buried depth and other parameters are verified, engineering treatment will be carried out

At present, there are many methods for karst soil cave exploration and positioning, such as geological drilling, geological radar, shallow seismic longitudinal wave reflection method, hole collapse elastic wave CT, high-density electrical method, microgravity, etc.; It is the most direct method to drill a hole, but its cost is high, the detection position is random, and there is a "one-hole view" vision limitation. Often no soil hole is found at the drilled hole position, and as a result, a subsidence occurs next to the drilled position. To achieve large-scale For general survey, it is necessary to reduce the drilling hole spacing to 2-3m / hole, assuming a general survey of 1km 2 area, about 110,000 holes need to be arranged, which is obviously unscientific; for physical detection methods such as geological radar, shallow seismic longitudinal wave reflection method, hole collapse elastic wave CT, high-density electrical method, and microgravity, they have similar The advantage is that it can carry out detection of several kilometers at a time, and the work efficiency is higher than that of geological drilling methods, but there are still many disadvantages. First, it is more restricted by surface vegetation, large surface water bodies and buildings (structures). Second, the linear survey can only be carried out at one time. To realize the planar general survey, it is necessary to arrange a lot of parallel lines, and the distance between the parallel lines generally does not exceed 5m. This is very complicated to implement and the cost is very high. Third, the accuracy of the geophysical survey results is relatively low. Low, the accuracy of the interpretation results depends on the technical level and engineering experience of the interpreters, so the current geophysical prospecting methods are only suitable for fine detection in small areas or rough detection in large areas

[0004] To sum up, it is very difficult to find and locate underground karst caves with large area, low cost, easy operation and high accuracy in terms of the karst soil cave exploration methods commonly used in practical engineering at present.

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