一、前言“七五”期间,长江三峡工程坝区外围深部构造研究发现三斗坪坝址区基岩的纵波P_g、横波S_g存在异常信息,因此,在“八五”期间通过乐天溪试验炮,在乐天溪—三斗坪—太平溪之间进行了T字型削面检验,获得三斗坪坝址北缘地区P_g、S_g和面波R_g的发育状态。这不仅证实了太平溪—乐天溪之间存在异常地质结构,而且揭示出该异常结构 I. INTRODUCTION During the “Seventh Five-Year Plan” period, the study on the deep structure of the periphery of the dam area of ​​the Three Gorges Project in the Yangtze River discovered that the P_g and S_g of bedrock of the Sandouping dam site were abnormal. Therefore, during the “Eighth Five-Year Plan” period, T-shaped facet inspection was carried out between Lotte Creek, Sandouping and Taipingxi, and the developmental status of P_g, S_g and R_g in the northern margin of Sandouping dam site was obtained. This not only confirmed the existence of anomalous geological structure between Taipingxi-Lotten Creek, but also revealed the abnormal structure