干湿循环下石灰黄土垫层透水性和强度变化试验

Test study on the permeability and strength variation of lime loess bedding under wetting and drying cycles

针对西安大明宫国家遗址公园御道工程透水混凝土灰土垫层的设计要求,分别进行了干湿循环10次下石灰黄土35 d龄期时单轴抗压强度试验、变水头渗透性试验和快速直接剪切试验。试验结果表明:若忽略含水量的影响,灰土快速直接剪切试验抗剪强度和渗透系数均随干湿循环次数增加呈指数型衰减,且较快趋于稳定收敛,其拟合曲线和公式均与实测数据吻合良好;若忽略试样含水量的影响,石灰黄土35 d龄期单轴抗压强度随干湿循环次数变化规律不太明显,单轴抗压强度变化不大,说明该石灰掺量(干石灰占干土料百分比为15%)下处理马兰黄土得到的石灰黄土35d龄期单轴抗压强度在干湿循环下的稳定性较好。

Based on the design parameters of lime soil bedding under permeable concrete in imperial road engineering,in Xi＇an Da Ming Gong national archaeological site park,the uniaxial compressive test,variable head permeability test and fast direct shearing test of lime loess on age 35 d were accomplished under ten wetting and drying cycles.Test results shows that,the fast direct shearing strength and permeability coefficient both decrease exponentially with the number of wetting and drying cycles if without consideration of moisture content,and the fitting curve and equation is according with the measured values well.Furthermore,the influence of wetting and drying cycles on the uniaxial compressive strength on age 35d is not obvious if without consideration of the moisture content of lime loess,with small variation of uniaxial compressive strength,which justify that the uniaxial compressive strength on age 35d of lime loess treated with lime of dry mass ratio 15% is stable under wetting and drying cycles,and the moisture content of lime soil is influent to the variation rule of the uniaxial compressive strength with the wetting and drying cycles.