Study Of One-dimensional Consolidated Theory And Undrained Plane With Continuous Drainage Boundary

In the actual project,the existing method of consolidating soft soil foundation is mainly vacuum pre-pressure drainage consolidation method.This soft soil foundation treatment method is mainly through the vertical drainage body-inside the soil body,increasing the internal drainage rate of the soil body,and laying a horizontal sand cushion on the surface,so as to achieve the purpose of reinforcing soil quickly.However,there are few horizontal drainage bodies inside the soil body,which changes the horizontal drainage boundary inside the soil body and increases the vertical drainage rate.Especially in the process of reclamation of dredger fill,the dredger fill has the characteristics of high natural moisture content,large void ratio,high compressibility and low permeability,etc.If the horizontal drainage body is set in advance during the filling process of the dredger filling,the drainage rate in the vertical direction of the soil body is accelerated,which is of great significance for accelerating consolidation of the dredger filling soil.And study where the horizontal drainage body inside the soil makes the soil consolidation the fastest,we need to understand the distribution and dissipation law of the pore water pressure inside the soil,the distribution and the dissipation of the pore water pressure inside the soil is closely related to the drainage boundary,initial pore water pressure and the soil properties of the soil,this article is to carry out research work layer by layer in these areas.Firstly,according to the distribution of pore water pressure inside the soil,an undrained surface is defined,and the consolidation theory and undrained surfaces of the continuous drainage boundary are studied.Then the characteristics of the initial pore water pressure special distribution of the soil are further considered,and the one-dimensional consolidation theory and its undrained surface of the continuous drainage boundary with initial pore water pressure special distribution were solved and analyzed.Finally,the consolidation problem of the horizontal drainage body inside the soil was solved.The main conclusions are as follows:1.When the drainage capacity of the upper and lower permeable surfaces is the same,the pore water pressure is symmetrically distributed and dissipated,and the undrained surface is in the middle of the soil layer,which is not affected by the permeability coefficient and compression coefficient,and does not move;but when the drainage capacity of.the upper and lower permeable surfaces is not the same,the undrained surface will move toward the pervious surface with weak drainage capacity,and the undrained surface will be greatly influenced by the permeability coefficient and compression coefficient.2.When considering the special distribution of the initial pore pressure according to the actual project conditions,for the initial pore pressure inverted triangle distribution,inverted trapezoidal distribution,positive trapezoidal distribution,and equilateral triangle distribution,even if the pervious surface has the same permeability,the pore water pressure inside the soil layer is not symmetrical distribution,the undrained surface is not in the middle of the soil layer,but moves from the side where the initial pore water pressure is large to the middle of the soil layer,and the permeability of the permeate surface affects the drainage rate on the side where the initial pore pressure is large,it is much larger than the side where the initial pore water pressure is small.3.For the initial pore water pressure inverted triangle distribution,inverted trapezoidal distribution,positive trapezoidal distribution,and equilateral triangle distribution,the position of the horizontal drainage body should be close to the side where the initial pore water pressure is large,and the consolidation speed of the soil is the fastest.The initial pore water pressure rectangular distribution should be set in the middle of the soil layer horizontal drainage body,soil consolidation rate is the fastest.