Evaluation methods for dynamic deformation-strength-crushability properties of volcanic granular soils

对取自火山粗粒土的原状和扰动样进行了一系列的室内试验，以获得其循环不排水三轴强度、伪弹性剪切模数、阻尼比和剪切诱发颗粒破碎等力学性能。此外，还对自然沉积的火山岩地面进行了现场调查，采用SPT、CPT、膨胀仪试验、地震锥体试验和PS测井。得出以下结论：(1)利用有效应力比和有效平均主应力，可以方便地估算任意应力路径下固结和剪切引起的颗粒破碎量。(2)在颗粒破碎显著的火山土中，应力历史引起的循环变形-强度行为的变化更加明显。(3)揭示了颗粒破碎、胶结作用和沉积环境对测深数据与室内变形强度参数相关性的影响。

A series of laboratory tests on the undisturbed and disturbed samples taken from volcanic coarse-grained grounds were carried out to obtain the mechanical properties such as cyclic undrained triaxial strength, pseudo elastic shear modulus, dampimg ratio and shear-induced particle crushing In addition to these laboratory tests, site investigations were also conducted at the naturally deposited volcanic grounds, using SPT, CPT, Dilatometer test, Seismic Cone Test and PS logging. The following conclusions were obtained; (1) Amount of particle breakage induced by consolidation and shearing in arbitrary stress paths can be estimated easily by effective stress ratio and effective mean principal stress. (2) Variation in cyclic deformation-strength behaviors due to stress history was observed more clearly in the volcanic soils with which particle breakage has been significantly induced. (3) Effects of particle breakage, cementation and sedimentary environment on the correlation between the sounding data and deformation-strength parameters evaluated from laboratory tests are revealed.