Method for determining soil permeability coefficient on basis of piezocone sounding

Abstract

The invention provides a method for determining a soil permeability coefficient on the basis of piezocone sounding. The method includes steps of firstly, determining the depth of a piezocone sounding hole, the radius of a conical head and the underground water level of a field according to a piezocone sounding report and determining division of soil layers by a Robertson soil layer classification map; secondly, acquiring soil samples from the different soil layers, testing densities of the soil samples and determining unit weights of the soil layers; thirdly, determining piezocone sounding standard parameters which include pore water pressure ratios and standard tip resistance according to parameters obtained in the first step and the second step; fourthly, determining a permeability coefficient index according to the piezocone sounding standard parameters acquired in the third step; fifthly, determining coefficients of the soil layers in initial radial distribution of excessive pore pressure according to the division of the soil layers; and sixthly, determining the soil permeability coefficient according to results obtained from the first step, the second step, the third step, the fourth step and the fifth step. The method has the advantages that the soil permeability coefficient can be accurately determined, and the method brings great convenience for survey and design for soil permeability.

Description

technical field [0001] The invention relates to a method in the technical field of construction engineering, in particular to a method for determining soil permeability coefficient based on pore pressure static penetration testing. Background technique [0002] Soil permeability coefficient is an important parameter in geotechnical engineering design such as foundation pit dewatering design, foundation settlement estimation, and slope stability analysis. Accurately obtaining soil permeability coefficient has important engineering practical significance. The methods for determining soil permeability coefficient in engineering mainly include laboratory test and field test. There are many disadvantages in the indoor test: 1) The disturbance of the soil sample is large; 2) The field conditions cannot be accurately simulated; 3) The workload is heavy, the test time is long, and the cost is high. There is a large difference between the permeability coefficient measured in the lab...

AI Technical Summary

Problems solved by technology

There are many shortcomings in the indoor test: 1) The disturbance of the soil sample is large; 2) The field conditions cannot be accurately simulated; 3) The workload is large, the test time is long, and the cost is high

[0004] After searching the existing technical documents, it is found that "Permeability determination from on-the-fly" published by Elsworth et al. in "Journal of Geotechnical and Geoenvironmental Engineering" (2005, Vol. piezocone sounding (quick determination of permeability based on pore pressure static sounding)" gives a semi-theoretical and semi-empirical determination method, but this method is only applicable to soil with partial drainage conditions and sandy soil with good water permeability

Based on Elsworth’s research, Chai et al published “Estimating hydraulic conductivity from piezocone sounding” (calculation of permeability coefficient based on pore pressure static sounding) published in “Géotechnique” (2011, Vol.61, No.00pp.1-10) in 2011. " also gave a method to determine the permeability coefficient, but this method relies on experience and assumes that the initial excess pore pressure distribution function is suitable for a specific viscous formation, and the test results obtained are very different from those in my country, so it is difficult to apply directly

Images