干湿循环对新型固化土承载强度影响的试验研究  

EXPERIMENTAL STUDY OF INFLUENCE OF DRYING AND WETTING CYCLES ON BEARING CAPACITY OF IMPROVED SOIL BY CMSC SOIL STABILIZED AGENT

作　　者：郑军[1] 阎长虹[1] 夏文俊[2] 张义贵[3] 崔大伟[2] 周欣[2] 张睿[3] 陈明珠[1] 

机构地区：[1]南京大学地球科学系,江苏南京210093 [2]江苏省高速公路建设指挥部,江苏南京210004 [3]淮安市高速公路建设指挥部,江苏淮安223001

出　　处：《岩石力学与工程学报》2009年第A01期3051-3056,共6页Chinese Journal of Rock Mechanics and Engineering

基　　金：江苏省交通厅科技开发资助项目(2006-45-3);教育部高等学校博士学科点专项科研基金资助项目(20070284006)

摘　　要：通过模拟一些地区季节性干湿交替的气候变化特征,利用新型击实筒制样进行试验,研究干湿循环对新型固化土承载强度的影响。测试新型固化土在干湿循环交替作用过程中的吸脱湿水量和承载强度,系统分析试件的吸水量、膨胀量和失水量的变化规律以及干湿循环次数对加州承载比值的影响机制。结果表明:在干湿循环作用初期,养生作用促进了固化剂的进一步反应,增强土粒之间的胶结强度,固化土的承载强度表现为逐渐增大,干湿循环达4次时其强度升至峰值;循环超过4次后,以含水量的变化与裂隙性的双重作用为主,促进细微裂纹的扩张、贯通,新裂纹的产生,降低试件的整体性和均一性,其承载强度逐渐衰减。On the basis of simulating the seasonal climate which alternates between dryness and wetness in some places, making use of the new hit canister to produce the samples, group of tests were performed to study the influence of drying-wetting cycles on beating capacity of improved soil by CMSC soil stabilized agent. During the process of drying and wetting cycles, the dehydration mass, water absorption mass and California bearing ratio （CBR） of improved soil by CMSC soil stabilized agent were tested. The variation of dehydration mass, water absorption mass and swelling rate, and the influencing mechanism of numbers of drying-wetting cycles on the CBR value were analyzed. It was shown that during the initial stages of drying and wetting cycles, the curing time and the fitting temperature provided by the dehydration process could accelerate the full reaction between the CMSC soil stabilized agent and soil. Meanwhile the cementation between soil particles was strengthened. So along with the process of drying and wetting cycles, the bearing capacity of improved soil increased. And when the number of drying-wetting cycles was 4, the bearing capacity reached the maximum CBR value. When the number of drying-wetting cycles was greater than 4, the actions are coupled of the variable water content and fissures, and the thin fissures were distended and ran through： then the new fissures came into being. So the unitary andhomogeneous property of samples were broken and the bearing capacity of improved soil decreased gradually.

关 键 词：土力学 CMSC型固化剂 干湿循环 新型击实筒 加州承载比 

分 类 号：TU43[建筑科学—岩土工程]