Abstract:

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.

Key words: rectangular closed diaphragm wall, wall group effect, wall group efficiency, settlement ratio, wall spacing