On the in-situ soil property evaluation method by electronic cone penetration testing

电子贯入测试(ECPT)是世界上广泛使用的现场地面勘察技术，用于确定准确的土壤剖面和提供定量的土壤性质。静力触探试验的主要目的是获得软土的不排水抗剪强度(S_U)和超孔隙水压力等力学性质的数据。S_u的值通常由室内试验获得，包括由于样品搬运、不同的程序、各种室内试验和S_u的测定技术而引起的一些扰动值。为了获得原状强度数据，需要对扰动后的土样进行过滤。在本研究中，提出了以变形模数(E&lt；50)和超孔压(U_D)为函数的过滤方程，并将其应用于Ariake粘土场地，去除了E&lt；50&gt；和u_d分别被认为是由粘土强度和结构扰动引起的扰动较大的S_u值。将过滤后的S_u值与阿里克粘土场地的ECPT数据预测的S_u进行了比较，得到了较好的一致性。

The Electronic Cone Penetration Testing (ECPT) is world-widely used as as in-situ ground investigation technique for determining accurate soil profiles and providing quantitative soil properties. The main purpose of ECPT is to obtain data on mechanical properties like undrained shear strength (S_u ) and excess pore water pressure of soft cohesive soils.The values of S_u, which are obtained from laboratory tests, usually include some disturbed values due to sample transportation, different procedure, various laboratory tests and the technique of determination of S_u. To obtain undisturbed strength data, filtering the samples from disturbed soil is needed. In this research, the filtering equation which is expressed as the function of the deformation modulus ( E_<50> ) and the excess pore water pressure ( u_d ) is proposed as a simple equation and applied for Ariake clay sites to remove the s_u values which are considered to be rather disturbed in which E_<50> and u_d are considered to depend on the disturbance of strength and structure of clay, respectively.The filtered selected s_u values were compared to find fairly good agreement with the s_u predicted by the ECPT data for Ariake clay sites.