Diaphragm wall-soil-cap intεraction in rectangular-closed-diaphragm-wall bridge foundations

摘要

Rectangular-closed-diaphragm-wall founda-tion is a new type of bridge foundation. Diaphragm wall-soil-cap interaction was studied using a model test. It was observed that the distribution of soil resistance under the cap is not homogeneous. The soil resistance in the comer under the cap is larger than that in the border; and that in the center is the smallest. The distribution of soil resistance under the cap will be more uniform, if the sectional area of soil core is enlarged within a certain range. Due to the existence of cap, there is a "weakening effect" in inner shaft resistance of the upper wall segments, and there is "enhancement effect" in the lower wall segments and in toe resistance. The load shearing percentage of soil resistance under the cap is 10%-20%. It is unreasonable to ignore the effects of the cap and the soil resistance under the cap in bearing capacity calculations.