竖向荷载下矩形闭合地下连续墙桥梁基础群墙效应研究

矩形闭合地下连续墙基础（简称闭合墙基础）是一种新型的桥梁基础。通过室内模型试验，对闭合墙基础的群墙效率、沉降比等进行了研究，同时探讨了闭合墙墙间距（即内侧边长）对群墙效应的影响。试验中采用了2组不同截面尺寸的模型墙，其中A组模型墙边长小于B组模型墙，墙厚和墙高均相同。试验研究表明，闭合墙与单片墙在相同沉降下的荷载比一般都大于1，B组闭合墙荷载比和群墙效率均大于A组闭合墙；闭合墙与单片墙在相同墙顶应力下的位移比和沉降比基本都大于1，A组闭合墙位移比大于B组闭合墙。在保持墙厚和墙高不变的情况下，适当增大闭合墙基础的内侧边长可以有效地提高群墙效率和承载性能，从而获得更好的经济效益。

Research on wall group effect of rectangular closed diaphragm wall as bridge foundation under vertical loading

Rectangular closed diaphragm wall foundation is a new type of bridge foundation. Wall group efficiency and settlement ratio and influence of wall spacing on wall group effect were studied through a model test. There were two groups of model walls in the test, all of the walls had same thickness and height, but side length of model walls in group A was less than that in group B. It was observed that the load ratio of closed diaphragm wall and single diaphragm wall with the same settlement was always large than 1; further more, the load ratio and wall group efficiency of closed diaphragm wall B was more lager than closed diaphragm wall A. The settlement ratio of closed diaphragm wall and single diaphragm wall with the same head pressure was also large than 1; and the settlement of closed diaphragm wall A was more lager than closed diaphragm wall B. Enlarging the wall spacing was a effective measure to improve the wall group efficiency and load-bearing capacity with the same wall thickness and wall height. Then better economic benefits would be obtained.