摘要
土工垫加筋草皮具有减小浅层滑坡和表面侵蚀的作用,为探究土工垫加筋草皮抗剪强度特性,在室内培育土工垫加筋生态草皮的基础上,对土工垫加筋草皮原状样进行了室内直剪试验,获得了土工垫加筋草皮剪切应力与位移关系曲线、抗剪强度参数等结果,并通过对比试验分析了土工垫和植被根系加筋量、土体含水量等对其抗剪性能的影响。试验表明:土工垫和根系共同加筋作用不会改变应力与位移关系曲线变化特征,但可显著提高加筋草皮的抗剪强度,在本次试验中与素土相比加筋后强度最大增幅为164.7%,强度增幅受法向应力水平影响显著,随着法向应力的增大,强度增幅逐渐减小;基于摩尔-库伦强度准则,获得了土工垫加筋草皮的黏聚力和摩擦角,结果显示加筋增加了草皮的黏聚力,但对内摩擦角几乎没有影响;随着加筋量的增大,土工垫加筋草皮的抗剪强度均近似按指数形式增大,加筋量越高土体抗剪强度增量也越大;低含水率试样对应的抗剪强度较大,含水率增大时,由于基质吸力降低,抗剪强度也会降低。研究成果对加筋草皮的推广应用具有参考价值。
Geotechnical mat(Geomat)reinforced turf has the effect of reducing shallow landslide and surface erosion.In order to explore the shear strength characteristics of Geomat reinforced turf,the indoor direct shear test was carried out on the original Geomat reinforced turf,and the relationship between the shear stress and displacement of the Geomat reinforced turf and the shear strength parameters were obtained.The effects of Geomat and vegetation root reinforcement,soil moisture content on shear performance were analyzed through comparative experiments.The test results showed that the joint reinforcement of Geomat and root system would not change the change characteristics of stress-displacement curve,but could significantly improve the shear strength of reinforced turf.In this test,the maximum increase of strength was 164.7%compared with that of plain soil,and the increase of strength was significantly affected by the normal stress level.As the normal stress increased,the intensity increased gradually.Based on the Mohr-Coulomb strength criterion,the cohesion and friction angle of Geomat reinforced turf were obtained.The results showed that reinforcement increased the cohesion of turf,but had little effect on the internal friction angle.With the increase of the amount of reinforcement,the shear strength of the Geomat reinforced turf increased approximately exponentially.The higher the reinforcement was,the greater the increment of shear strength of soil was.The low-water moisture content sample had higher shear strength,and when the water content increased,the shear strength decreased as the matrix suction decreases.The research results had reference value for the popularization and application of reinforced turf.
作者
徐毅
赵钢
陈佳
潘毅
XU Yi;ZHAO Gang;CHEN Jia;PAN Yi(Jiangsu Institute of Water Resources and Hydropower Research,Nanjing 210017,Jiangsu;College of Harbor,Coastal and Offshore Engineering,Hohai University,Nanjing 210098,Jiangsu)
出处
《江苏水利》
2019年第2期21-27,共7页
Jiangsu Water Resources
基金
国家自然科学基金项目(51639002)
江苏省水利科技项目(2016027)
关键词
土工垫
加筋草皮
抗剪强度
直剪试验
生态护坡
geotechnical mat
reinforced turf
shear strength
direct shear test
ecological slope protection
