加筋软岩粗粒土路堤填料大型三轴试验研究

 为研究加筋粗粒土填料的强度变形特性及加筋效果，进行加筋强风化软岩粗粒土固结不排水和固结排水大三轴试验。试验表明：加筋填料的应力–应变关系表现为应变硬化型；轴向应变较小(ea＜1%)时，加筋填料效果不明显，随着轴向应变的逐渐增大加筋效果逐渐发挥。加筋填料的孔隙水压力均高于素填料，随着加筋层数的增加均有不同程度的提高。加筋效果系数均＞1.0，一层加筋填料加筋效果系数为1.09～1.21，二层加筋填料加筋效果系数为1.30～1.71，三层加筋填料加筋效果系数为1.31～1.72。加筋前后填料的内摩擦角j基本不变，填料的黏聚力增大。加筋填料的本构关系可以用Duncan-Chang模型来描述，依据试验结果求得模型参数。

RESEARCH ON LARGE-SCALE TRIAXIAL TESTS ON REINFORCED SOFT ROCK COMPOSED OF COARSE-GRAINED SOIL AS EMBANKMENT FILLINGS

In order to study the strength and deformation properties of soft rock composed of coarse-grained soil,as well as its reinforcement effect as fillings,large-scale consolidated drained and undrained triaxial tests are carried out for reinforced intense-weathered rock. The results show that the stress-strain relationship of geotextile-reinforced fillings is of strain hardening. The geotextile-reinforced fillings have little effect while the triaxial strain is less than 1%,and the reinforcing effect becomes more remarkable with the increase of triaxial strain. The pore water pressures of geotextile-reinforced soil samples are higher than those of pure coarse-grained soil samples;and they increase with the increase of geotextile layers. The coefficients of reinforcing effect are all more than 1.0,being 1.09-1.21 while with one layer of geotextile;1.30-1.71 with two layers of geotextile and 1.31-1.72 with three layers of geotextile. The internal friction angle ψ of fillings before and after reinforcements is nearly constant,while the cohesion force of the fillings increases with the increase of geotextile layers. The constitutive relation can be described with the Duncan-Chang model;and the parameters of Duncan-Chang model for geotextile-reinforced soil are obtained through tests.