With excavation depth increasing

the problem of confined water has become more and more prominent

which has brought about adverse effect on the surrounding environment

such as bursting in foundation pit. To discover variation of confined water

reduce the amount of pumping

control ground surface settlement and protect the surrounding environment

based on the deep-large-irregular foundation pit Shanghai Museum of Natural History

confined water pumping test was carried out. The test results show that with excavation depth increasing confined water head is also lower; the barrier effect is not obvious if the depth of diaphragm walls inserted confined water layer was less one third than the thickness of confined water layer; head recovery ratio was described water level recovery

reached at 10% after 10 minutes

the ultimate reached at 94.5%; the relieve effect of single well was certain which was not related to the water head of test beginning

the relieve effect of group wells was related to well quantity however the relieve benefit became gradually worse. According to confined water pumping test

pumping wells can be grouped into different combinations; the excavation can be combined with different combinations at different times; then the goal will be achieved that pumping of confined water is released when needed.