The invention relates to the technical field of foundation pit observation, in particular to a foundation pit support crack deformation
observation system and method. According to the technical scheme, the device comprises a first
gasket arranged at the top of a left ground nail, the top of the first
gasket is rotationally connected with a reading ruler, the top of a right ground nail is provided with a second
gasket, the top of the second gasket is rotationally connected with a positioning ruler, and the reading ruler and the positioning ruler are staggered up and down. The height of the first gasket is changed by rotating the first lifting bolt, the height of the reading ruler is changed by rotating the second lifting bolt, so that the reading ruler and the positioning ruler are close to each other, the reading error is reduced, after the foundation pit crack is enlarged, the reading ruler and the positioning ruler move relatively, the exposed scale is the width of the foundation pit crack, a
mobile phone is used for shooting, and the detection accuracy is improved. The device can amplify observation readings on a computer, store reading pictures, regularly
shoot and observe crack changes in a period, is simple in structure, can be used by non-professional measurement personnel, and is high in
usability.