地震CT法在花岗岩球形风化残留体勘探中的试验研究

在城市盾构隧道建设过程中，盾构掘进若遇到花岗岩风化残留体（俗称孤石），掘进施工将非常困难，盾构姿态难以控制，刀具磨损严重，刀盘和刀座易变形，常常会出现喷涌、塌方、刀盘被牢牢卡住或刀盘严重磨损等意外情况。为保证盾构的顺利掘进，需采用物探方法探测出隧道沿线孤石分布情况。针对南方地区花岗岩地层特征，采用数值模拟和现场应用试验的方法开展花岗岩风化残留体的地震CT法探测技术研究，经钻探取芯验证与实际较吻合，解决了花岗岩风化残留体的准确探测与定位的难题。提出的一些合理化建议可为今后类似城市地铁工程施工提供参考。

Experimental Study on Seismic CT Method Used in Detection of Spherical Weathered Granite Residue

During the process of shield tunneling in cities, especially in weathered granite residue (boulder) containing strata, incidents, such as shield attitude deviation, serious wear of cutter tools, deformation of cutterhead and cutter, water burst, collapse and shield jamming, will inevitably happen. As a result, geophysical prospecting technology becomes more and more importantant to guarantee the success of tunneling. In this paper, the seismic CT method is studied based on the combination results of numerical simulation and site test. The core drilling results coincide with the actual geological conditions,and the accuracy of the detection technology is guaranteed. The suggestions proposed in this paper can provide reference for geophysical prospecting of underground works in the future.