ACCUMULATED DEFORMATION OF SAND WITH INITIAL SHEAR STRESS AND EFFECTIVE STRESS STATE LYING NEAR FAILURE CONDITIONS
ACCUMULATED DEFORMATION OF SAND WITH INITIAL SHEAR STRESS AND EFFECTIVE STRESS STATE LYING NEAR FAILURE CONDITIONS
复制标题
DOI：
10.3208/sandf.44.6_1
复制
发表时间：
2004-12
影响因子：
3.7
通讯作者：
Goran Arangelovski;I. Towhata
中科院分区：
文献类型：
--
作者：
Goran Arangelovski;I. Towhata
本文研究了静剪和循环应力作用下土体残余变形的发展。该问题在自然边坡、堤坝边坡、码头岸壁等情况下发挥着重要作用。其中，本研究特别侧重于静态剪应力循环不排水性能。此外，在具有静剪应力的结构中，在地震作用下，作用在剪切面上的力通常是单向循环荷载，而不改变其方向。试验研究的重点是单向循环加载（扭转应力加载仅在正侧或负侧）过程中剪应变在土单元中的累积。对相对密度为40%和60%的丰浦砂空心圆柱试件在有效压力为98 kPa、196 kPa和294 kPa的各向同性应力条件下以及各向异性应力条件下进行了一系列扭转剪切试验，以研究循环荷载过程中每循环的剪应变增量。静态剪应力水平设定为排水条件下极限应力的一半（安全系数等于2）。试验结果表明，静剪应力的存在使桑迪的阻力增大。每循环的剪切应变增量和循环次数的实验结果以对数标度绘制，以显示彼此的线性关系。基于这些发现，一个简单的模型预测的剪切应变。
This study concerns the development of residual deformations in soil subjected to static shear and cyclic stress components. This problem plays an important role in such situation as natural slopes, slopes of embankments and dams, quay walls. Among them, the present study focuses in particular on cyclic undrained behavior with static shear stress. Furthermore, in the case of structures with static shear stress and subjected to the earthquake shaking, the forces acting in the shear plane are generally one-way cyclic loading without reversing its direction. Experimental research was focused on the accumulation of shear strain in the soil element during one-way cyclic loading (torsional stress loading only on positive or negative side). Series of torsional shear tests on hollow cylindrical specimens of Toyoura sand with relative density of 40% and 60%, with isotropic stress condition under effective pressure of 98 kPa, 196 kPa and 294 kPa as well as anisotropic conditions were made in order to investigate the incremental shear strain per cycle during cyclic loading. The level of static shear stress was set equal to half of the ultimate stress under drained conditions (factor of safety equal to two). The experimental results showed that the presence of static shear stress increases the resistance of sandy soil. The experimental results of the shear strain increment per cycle and the number of cycles were plotted in a logarithmic scale to show a linear relationship with each other. Based on these findings a simple model for prediction of shear strain was developed.