粗粒土三轴试样端部约束影响研究

发布时间：2018-06-04 14:26

本文选题：粗粒土 + 三轴试验　；参考：《岩土工程学报》2017年S1期

【摘要】：对两种级配的砾石料,分别进行了两种中三轴固结排水剪试验,一种是试样端部采用润滑试样帽法以减轻端部约束对三轴试验的影响;另一种试样则是常规三轴固结排水剪试验,即不采取端部减摩措施。对比分析两种试验的结果,以研究端部约束对三轴试样变形及强度的影响,分析润滑试样帽法对粗粒土试样的端部减摩效果。结果表明:试样在剪切过程中均表现出不同程度的剪胀性,常规三轴试样体积变形比减轻端部约束试样体积变形略小;当试验围压较低时,减轻端部约束对试样偏应力峰值(σ_1-σ_3)_f影响相对显著,而高围压下,润滑试样帽法的减摩作用几乎消失;同样,内摩擦角φ,初始切线模量E_i,割线弹性模量E_1均比常规三轴试验的小;随着围压的不断增大,润滑试样帽法减轻端部约束的效果明显减弱。
[Abstract]:Two kinds of intermediate triaxial consolidation drainage shear tests were carried out for two grained gravel materials. One was that the end part of the specimen was lubricated by the method of sample cap to reduce the effect of the end restraint on the triaxial test. Another kind of specimen is the conventional triaxial consolidation drainage shear test, that is, no antifriction measures are taken at the end. In order to study the effect of end restraint on the deformation and strength of triaxial specimen and to analyze the antifriction effect of lubricating specimen cap method on coarse grained soil specimen, the results of the two tests were compared and analyzed in order to study the effect of end restraint on the deformation and strength of triaxial specimen. The results show that the specimens exhibit different degree of shear dilatancy in the shear process. The volume deformation of the conventional triaxial specimen is slightly smaller than that of the reduced end confined specimen, and when the confining pressure of the test is low, The effect of reducing the end constraint on the peak value of the specimen's deviant stress (蟽 1- 蟽 _ 3s) is relatively significant, but at high confining pressure, the antifriction effect of the lubricating specimen cap method almost disappears, similarly, the internal friction angle 蠁, initial tangent modulus E _ I, Secant elastic modulus E _ 1 are smaller than those of the conventional triaxial test. With the increasing of confining pressure, the effect of the cap method on reducing the end constraint is obviously weakened.
【作者单位】：江苏省秦淮河水利工程管理处;河海大学岩土力学与堤坝工程教育部重点实验室;中设设计集团股份有限公司;常州市建筑科学研究院股份有限公司;丽水学院工程与设计学院;
【基金】：浙江省自然科学基金项目(LY14E080004) 国家自然科学基金项目(51479052) 江苏省六大人才高峰项目(JZ-011)
【分类号】：TU41

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