Composite Consolidation Coefficient Analysis of Soft Soil with Drainage Water

The consolidation coefficient is the most basic parameter to calculate the consolidation rate of soil layer, and the horizontal consolidation coefficient controls the radial water flow into the drainage well. Based on the background of the soft soil in Shantou, Guangdong Province, a series of experimental studies on the consolidation characteristics were carried out by using the modified consolidation instrument. And the concept of the composite consolidation coefficient of the drained water body was put forward. The composite consolidation coefficient reflects the consolidation characteristics of soft soil with drainage water, The test results showed that: 1) The consolidation test with drainage plate is basically consistent with the load compression curve, but its consolidation rate is fast, which is reflected by the composite consolidation coefficient. 2) In the consolidation test of water bodies with drainage, the vertical consolidation coefficient and radial consolidation coefficient are calculated by “three-point method”, and then the composite consolidation coefficient is obtained. The composite consolidation coefficient decreases with the increase of drain spacing ratio, effective drainage diameter and drainage height, which is basically consistent with the theoretical formula. 3) The vertical consolidation coefficient and radial consolidation coefficient decrease with the increase of the diameter of the sample, and the difference is obvious when the load is large. The large-size model with a diameter of 100 mm and a height of 100 mm is about 1.35 times of the vertical consolidation coefficient of the conventional consolidation test.