Precipitation structure and precipitation construction method for deep foundation pit in near-water zone

According to the near-water zone deep foundation pit dewatering structure and the dewatering construction method, an underground diaphragm wall is arranged on the periphery of a deep foundation pit, the lower portion of the underground diaphragm wall is connected with a waterproof curtain of a jet grouting pile structure, and a plurality of dewatering wells are arranged on the inner side of the underground diaphragm wall; when the deep foundation pit dewatering structure is applied to deep foundation pit dewatering construction of an underground phreatic water layer or a confined water layer in a near-water zone with too large depth, the depth of the diaphragm wall is greatly shortened under the condition that the total waterproof curtain depth is guaranteed, so that the engineering cost of the diaphragm wall is greatly reduced; after the deep foundation pit is constructed, the diaphragm wall can be continuously used as a part of a deep foundation pit structure engineering structure, and the engineering struc