吹填泥浆固化及长期力学性能试验研究

Experiment study of solidification performance and long-term mechanical properties of dredger filled mud

利用粉末固化剂对天津滨海新区高含水率吹填泥浆进行固化试验,分析了含水率、龄期、固化剂掺量对吹填泥浆固化土强度的影响,基于试验结果确定了满足强度要求且经济合理的固化剂掺量为3%。以养护60 d的泥浆固化土无侧限抗压强度为基准,建立了无侧限抗压强度随水灰比和龄期变化的预测公式。通过三轴蠕变试验,对含水率为160%、养护28 d的泥浆固化土进行了长期特性分析,发现其蠕变特征与结构性软黏土接近,并利用等时曲线确定了其长期强度,在此基础上求得泥浆固化土在长期荷载作用下的抗剪强度指标,为吹填固化土的安全应用提供理论支持。

Solidification tests were performed on dredger fill mud with high moisture content in Binhai New Area of Tianjin using the powder curing agent.The effects of moisture content,curing time,and curing agent content on the strength of solidified soils were analyzed.The test results show that the most appropriate curing agent content is 3% considering the strength demand of economic rationality.The unconfined compressive strength with the curing duration of 60 days was defined as a benchmark.An equation for predicting unconfined compressive strength of the solidified soils was proposed using two variables,i.e.,water cement ratio and curing time.The long-term strength properties of solidified soils with the moisture content of 160% and the age of 28 days were analyzed by the triaxial rheological tests.The test results show that the solidified soils present similar creep behaviors to the structural soft clays.Meanwhile,the long-term strength of solidified soils can be determined using the isochronous curve.The shear strength indexes under long-term loads can also be determined,providing theoretical support for the security applications of solidified soils.