Abstract: The bearing characteristic of the closed diaphragm wall under horizontal load is complicated，because there is an interaction among soil core，walls and external soil． The model tests of three groups of four-chamber walls with different sizes were carried out． Based on the results on internal forces and displacement of the walls，the bearing characteristic of closed diaphragm wall foundation was investigated． For different sectional size and depth of closed diaphragm wall，the distribution of bending moment，shear force，rotation，soil resistance and friction resistance are in similar shape under various lateral loads． The bearing capacity of the wall increases with the increase of the wall sectional size and the depth． Closed diaphragm wall fails as rigid failure mode． The outer soil resistance of the front wall increases linearly with the horizontal load，which makes the most contribution to the soil resistance．

Key words: closed diaphragm wall, horizontal load, model tests

摘要： 井筒式地下连续墙基础因为存在土芯、墙体和外部土体的相互作用，其水平承载机理复杂。进行了3组不同尺 寸的四室模型墙试验。基于模型墙内力和位移测试结果，研究了其水平承载特性。结果表明不同截面尺寸和埋深的 井筒式墙基础在不同水平荷载下的弯矩、剪力、转角、土抗力以及摩阻力分布形状相似;随着墙体截面尺寸和深度的增 加，弯矩增大，墙体呈现刚体破坏特征;前墙外侧土抗力随荷载线性增加，成为土抗力的主要贡献部分。

关键词: 井筒式地下连续墙, 水平荷载, 模型试验