土工格室加筋黄土的三轴剪切性能

发布时间：2018-01-09 13:00

本文关键词：土工格室加筋黄土的三轴剪切性能　出处：《中国公路学报》2017年10期 　论文类型：期刊论文

【摘要】：为了研究土工格室加筋黄土的剪切性能,采用微型土工格室对不同加筋方式的格室加筋黄土及重塑黄土进行三轴剪切试验,得出加筋黄土及重塑黄土的应力-应变曲线及其抗剪强度指标,研究了加筋黄土和重塑黄土的应力-应变特性,分析了不同加筋方式下的加筋效果并讨论了不同土工格室层数加筋的加固机理。试验结果表明:重塑黄土和土工格栅加筋黄土的应力-应变曲线表现为弱硬化型,而土工格室加筋黄土的应力-应变曲线表现出明显的强硬化特性,4层土工格室加筋黄土的加筋效果最佳,2层土工格室加筋黄土在低围压、较大应变情况下,土工格室的加筋效果可以得到更好的发挥;重塑黄土和土工格栅加筋黄土的应力-应变曲线基本呈双曲线,用邓肯-张模型对其拟合效果很好,土工格室加筋黄土的应力-应变曲线用幂函数式对其逼近效果较好;土工格室加筋显著提高土体的摩擦角和黏聚力,2层土工格室加筋黄土的摩擦角和黏聚力相对重塑黄土分别提高38%和50%,4层土工格室加筋黄土的摩擦角和黏聚力相对重塑黄土分别提高63%和120%,均比土工格栅加筋黄土的高;土工格室的加筋效果优于土工格栅等平面筋材,且格室层数的增加能进一步提高黄土的剪切性能,其原因主要是土工格室"强化带"和"间接影响带"的存在,层数越多,"强化带"和"间接影响带"厚度越大,加筋黄土的抗剪强度会得到进一步提高。试验结果可为实际工程中设计参数的选取提供理论依据。
[Abstract]:In order to study the shear behavior of reinforced loess in geotextile, triaxial shear tests were carried out on the reinforced loess and remolded loess with different reinforcement modes in miniature geogrid chamber. The stress-strain curve and shear strength index of reinforced loess and remolded loess are obtained, and the stress-strain characteristics of reinforced loess and remolded loess are studied. The reinforcement effect under different reinforcement modes is analyzed and the reinforcement mechanism of different layers of geogroups is discussed. The experimental results show that:. The stress-strain curves of remolded loess and geogrid reinforced loess are weakly hardened. The stress-strain curve of geogrid reinforced loess shows obvious hardening characteristics. The reinforcement effect of the reinforced loess in 4 layers geotextile chamber is the best under the condition of low confining pressure and large strain. The reinforcement effect of geogroups can be played better; The stress-strain curve of remolded loess and geogrid reinforced loess is basically hyperbolic. The stress-strain curve of geogrid reinforced loess is approximated by power function. The friction angle and cohesive force of reinforced loess in geogrid chamber are significantly increased by 38% and 50%, respectively, compared with that of remolded loess. The friction angle and cohesion of the reinforced loess in the four layers of geogrid are increased by 63% and 120, respectively, which are higher than those of the geogrid reinforced loess. The reinforcement effect of geogrid is better than that of plane reinforcement such as geogrid, and the shear behavior of loess can be further improved by increasing the number of lattice layers, which is mainly due to the existence of "strengthening zone" and "indirect influence zone" in geogrid. The more layers, the thicker the "strengthening zone" and "indirect influence zone", the shear strength of reinforced loess will be further improved. The test results can provide a theoretical basis for the selection of design parameters in practical engineering.
【作者单位】：长安大学公路学院;宁波正信检测科技有限公司;
【基金】：国家自然科学基金项目(41272285) 甘肃省科技重大专项项目(1302GKDA009) 甘肃省交通运输厅科技项目(2017-002)
【分类号】：U412.22
【正文快照】： 0引言土工格室是20世纪80年代初出现的一种新型土工合成材料,其是由高密度聚乙烯或聚丙烯共聚物片材经超声波焊接而成的三维网状结构物。相比一般的土工合成材料,土工格室具有整体强度较高、化学性能稳定、适应性强等特点[1],而且由格室提供的侧限作用可以显著提高粗粒土的剪

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