Monitoring and Prediction Analysis of Settlement for the Substation on Soft Clay Foundation

The bearing capacity of soft clay foundations is low, which easily causes excessive cumulative and uneven settlement of the substation. This will seriously threaten the safe operation of equipment in the substation. Based on a 220-kV substation project in a coastal soft clay ground, the settlement of the substation building is monitored on the spot, and the settlement law of soft clay ground is analyzed. Furthermore, a three-dimensional finite element model is developed using finite element software named ZSOIL.PC. A numerical model for predicting the settlement of soft clay ground in a substation is proposed using the appropriate element type, material constitutive model, and calculation parameters. The rationality of the numerical method is validated by comparison with the measured data. After improving the soft clay ground with the cement-soil deep mixing method, there are still certain degrees of cumulative and differential settlements in the substation distribution device building, but both are within the specification requirements. The settlement of the soft soil ground in the substation increases with time, but the growth rate gradually decreases and ultimately tends to stabilize after a certain period of time, ensuring the uniformity of foundation treatment is the key to controlling the differential settlement. The research results can provide a reference for the subsequent installation and construction of electrical equipment and the design of substation engineering in soft soil ground.