加筋条件和含水率对加筋土抗压强度和应力应变的影响  

Effect of Reinforcement Condition and Water Content on Compressive Strength and Stress-Strain of Compaction Soil with Wheat Straw

作　　者：王生新[1] 柴寿喜[2] 王晓燕[3] 

机构地区：[1]甘肃省科学院地质自然灾害防治研究所,兰州730000 [2]天津城市建设学院天津市软土特性与工程环境重点实验室,天津300384 [3]中水北方勘测设计研究有限责任公司勘察院,天津300222

出　　处：《吉林大学学报（地球科学版）》2011年第3期784-790,共7页Journal of Jilin University：Earth Science Edition

基　　金：天津市自然科学基金项目(07JCYBJC12900);国家自然科学基金项目(40772166);甘肃省科学院基金项目(2008YS-JK-15)

摘　　要：由滨海盐渍土的盐胀、溶陷和吸湿软化引起的土的低强度和大变形问题,可通过麦秸秆加筋的方法予以应对。加筋土的抗压强度及应力应变特性与麦秸秆的加筋长度、加筋率和土的含水率有关。加筋土的抗压强度试验结果证实:0.25%加筋率的加筋土抗压强度最大,0.20%和0.30%的次之;50 mm加筋长度加筋土的抗压强度最大,70 mm的最小。0.25%加筋率的加筋土应力应变曲线的峰值最大;随加筋长度的增加,加筋率对应力应变的影响程度降低。随加筋长度的增加,加筋土的应力应变曲线由应变软化型渐变为应变硬化型,以70 mm加筋长度的最为明显。低于最优含水率,应力应变曲线存在峰值;高于最优含水率,加筋土逐渐转向塑性变形。总结麦秸秆加筋土的抗压强度和应力应变的变化规律,为后期的三轴抗剪强度及其偏应力应变特性研究提供借鉴。Inferior strength and more deformation resulted from salt expansion,dissolution and water absorption,are overcome by means of reinforcement with wheat straw.Reinforced ratio,reinforced length and water content of soil influence the compressive strength of heavy compaction specimen and its stress-strain.It has been proved that（1）compressive strength of reinforced soil with 0.25% ratio is the best,those with 0.2% and 0.3% are better,peak of stress-strain curve of reinforced soil with 0.25% is remarkable;（2）effect of reinforced ratio on stress-strain is more and more weaker with the increase of reinforced length;（3）type of stress-strain curve changes gradually from strain softening to strain hardening with the increase of reinforced length,in which that with 70 mm is obvious;and（4）there is a peak in stress-strain curve of reinforced soils below optimum water content,and that above optimum water content display gently plasticity.Analysis on regulation of unconfined compressive strength and stress-strain will provide some directions for studying triaxial shear strength of reinforced soils with wheat straw and its deviator stress-strain in next stage.

关 键 词：抗压强度 应力应变 加筋条件 含水率 麦秸秆 盐渍土 重型击实 

分 类 号：TU443[建筑科学—岩土工程]