软土路基的沉降观测

广州南部地区(仑头一龙穴岛)快速路路基工程多为软土路基,其路基处理形式多样。在新龙特大桥北侧(K62+475.5～K63+770.007)设立试验段,采用粉喷桩、浆喷桩、塑料排水板处理方案,通过埋设的试验元件观测软土路基,分析研究水泥土不同掺灰量的不同龄期的物理力学性质及复合地基沉降、桩间土孔隙水压力的形成与消散、桩土应力的变化规律。解决在软土地基上较短时间内修建快速路的一系列难题,确定合理的软基处理方案、填土速率控制标准和工后沉降预测方法等。

Settlement Observation of the Soft Subgrade

Most of the subgrade under the expressway in the southern Guangshou Province belongs to soft subgrade and there are various methods to treat it. Experimental section in the north part of Xinlong Bridge is treated by dry jet pile, concrete jet pile and plastic drain plate together, the embedded testing elements are used to observe sotflement of the subgrade; the physical mechanical properties of soil with different cement-addition contents at different ages are rosearehad; problems such as settlement of the compound foundation, the formation and dispersing of the pore-water pressure as well as the change regulations of the interpih soil are also studied. The ditllcultios to construct expressway above soft subgrade in a short time are resolved when the soft subgrede is treated appropriately, standard earth filling rate is made and settlement of subgrade is well forecast.