Research on the safety of the upstream cofferdam structure of kala hydropower station

The safety of the cofferdam structure is of great significance for ensuring the smooth construction of dams, but the construction of cofferdams also faces significant safety risks. This article conducts three-dimensional finite element static calculation and analysis on the upstream cofferdam of Kala Hydropower Station. The calculation results show that the partition design of the cofferdam section is reasonable. The existing cofferdam construction plan is safe and feasible. When the top of the cofferdam flows for the second time, the stress and deformation of both the cofferdam body and the concrete impermeable wall will reach their maximum values and meet the requirements of the specifications. The maximum settlement of the dam body is 23.6cm, accounting for 0.4% of the maximum dam height. The maximum horizontal displacement downstream in the river direction is 20.4cm. The extreme values of the first and third main stresses are 1.36 MPa and 0.58 MPa, respectively. The shear stress level of each working condition is always less than 1. The concrete anti-seepage wall has a small tensile stress zone at the bottom due to slight deformation, but it is still within the tensile strength range of the concrete. The conclusion can provide a reference for the design and construction of similar cofferdam projects.