匀速等量堆载的真空联合堆载预压下吹填土工程特性试验研究

Experimental Study of Engineering Properties of Dredger Fill under Vacuum Pressure and Surcharge Load of Uniform and Equivalent Loading

针对温州滩涂围垦区吹填土处理难度大、强度低、工期长等问题,在真空-堆载联合预压下,采用5 k Pa/d匀速堆载的方式进行室内模型试验;同时设立真空预压对照组。对真空度、孔隙水压力、表层沉降进行监测并分析变化原因。通过加固后的土体含水率和十字板剪切强度对加固效果进行对比分析。试验结果表明:真空-堆载联合预压处理技术能够又快又好地加固温州吹填土。匀速堆载时真空度、孔压和土体表面沉降有明显变化;但随着时间推移而减弱。加固效果优于真空预压。

Aiming at the questions that coastal reclamation area dredger clay in Wenzhou is difficulty to improve,the strength requirements is hard to satisfied with,the improvement period is long,etc. The indoor model test was carried out by 5 k Pa/d uniform loading method under vacuum pressure and surcharge load while the vacuum preloading model test was set upand subject to large amount of observations,including vacuum degree,pore water pressure and surface settlement. Based on the test data,change laws of vacuum degree,pore water pressure and surface settlement were analyzed under uniform and equivalent loading. Moreover,both of the treatment methods was compared by the soil moisture content and the vane-shear strength. Results indicate that the soft soil foundation in coastal reclamation area can be reinforced by vacuum pressure combined with surcharge load fast and excellently.When loaded at constant speed,vacuum pressure,pore pressure and soil surface subsidence have changed significantly but weakened with the passage of time. The reinforcement effect of soil are also superior to ordinary vacuum preloading method.