一、前言三峡工程溢流坝段的结构型式为多层、多孔口的复杂空间结构,而坝基又有一条大花岗岩脉横穿整个坝段。根据这一实际情况,本文论述了用两个平面地质力学模型试验技术研究溢流典型坝段(18号坝段)扬压力对坝体稳定形式及位移的影响,同时用三维地质力学模型研究典型坝段(18号坝段)受邻近坝段(17、19号坝 I. INTRODUCTION The structure type of overflow dam section of the Three Gorges Project is a complex space structure with multi-layer and multi-orifice, and another large granite vein runs across the whole dam section at the dam foundation. According to the actual situation, this paper discusses the effect of the two typical planar geomechanical model test techniques on the stability of the dam form and displacement caused by the uplift pressure of the typical dam section (section 18). At the same time, using the three-dimensional geomechanical model, The dam section (section 18) is adjacent to the dam section (section 17,19)