Case analysis and study of comprehensive geophysical methods in urban deep buried pipeline detection in soft soil regions of Zhejiang province
With the wide application of trenchless technology,the problem of fine detection of urban deep-buried pipelines is particularly prominent.Especially in urban areas rich in soft soil and underground water,the traditional ground pipeline de-tection technology has weak anti-interference ability,low signal-to-noise ratio,insufficient detection depth,and other problems when detecting deep buried pipelines,and often fails to achieve good detection results.In this study,the borehole magnetic gradient method,cross-hole resistivity CT method,cross-hole acoustic transmission method,and other borehole geophysical prospecting methods are mainly used,and the conventional ground geophysical prospecting technology is supplemented.Many different types of deep buried pipeline detection research have been carried out in the soft soil area of Zhejiang Province.Some understanding has been obtained:the borehole magnetic gradient method and cross-hole ultrasonic method can accurately iden-tify the plane position and buried depth of the deep-buried pipeline,with the accuracy of several centimeters.The borehole magnetic gradient method is only effective for deep-buried magnetic metal pipelines.The cross-hole acoustic transmission method can adapt to the deep-buried pipelines of various materials,but it has specific requirements for the cross-hole distance.Generally,the effect is better if the hole spacing is less than 8m in soft soil areas.The cross-hole resistivity CT method has rel-atively low requirements for hole spacing,but this method has the problem of volume effect.The resistivity anomaly is often more significant than the target body,and the detection resolution is relatively low.Considering that the urban shallow area is a human disturbance layer and there are many kinds of interferences,in order to eliminate the multi-solution of geophysical prospecting technology,it is recommended to use more than two kinds of borehole geophysical prospecting technology to detect and verify each other when conditions permit,to obtain more reliable and precise detection results.
国家科技期刊平台
NSTL
万方数据
