Method for testing stability of pit bottom of foundation pit with confined water stratum

The invention provides a method for testing the stability of the pit bottom of a foundation pit with a confined water stratum. The method for testing the stability of the pit bottom of the foundation pit with the confined water stratum comprises the following steps that (1) the shape and size of an enclosure plate are determined; (2) the depth and thickness of the foundation pit are determined; (3) soil layers are laid layer by layer, and the enclosure plate is buried; (4) a monitoring network is partitioned; (5) a data acquisition system is mounted; (6) water is added through a water inlet, so that the water level is made higher than the position of an inverse filtering plate; (7) the tested maximum water pressure value is determined according to the water pressure of an actual pressure bearing layer; (8) the air pressure loading level is determined; (9) the air pressure is loaded; (10) data are measured and recorded by the data acquisition system; (11) the air pressure on another level is adjusted, and data are measured and recorded; (12) loading is stopped when seepage destruction starts to occur on the bottom surface of the pit; and (13) a relational graph between the water pressure and deformation of the pit bottom is drawn. According to the method for testing the stability of the pit bottom of the foundation pit with the confined water stratum, the effect is good, operation is convenient, the construction period is short, and the cost is low.