不同填料下钱塘江古海塘塘背土压力现场试验研究

为解决钱塘江古海塘外倾问题,结合现场试验,分别对气泡混合轻质土(以下称为轻质土)、原状土和页岩陶粒等3种不同填筑材料下古海塘塘背土压力进行了观测,分析了土压力随时间的变化规律,以及土压力的分布规律和合力作用点的位置,并对3种不同填筑材料的减载效果进行了分析。结果表明:土压力呈中间大、两端小,在塘背中部存在着不同程度褶曲的非线性分布;土压力合力作用点在0.42⁰.49倍墙高处,较理论计算的合力作用点位置有所上移;采用轻质土作为填料时,其产生的塘背土压力和倾覆力矩较原状土分别减少33.1%和41.4%,是一种有效的古海塘塘背土压力的减载材料。

Field test on earth pressure of ancient seawall with different backfills for Qiantang River

In order to solve the inclined problem of the ancient seawall, the earth pressure on the ancient seawall with different types of backfills are observed based on the in-situ test. Three types of ancient seawall are filled with different backfills as the foamed cement banking (FCB), natural soil and shale ceramisite respectively. The law that the earth pressure changed with time is analyzed, also including the distribution of the earth pressure and the location of resultant force point. The unloading effects of the three different filled materials are discussed. The distribution of earth pressure is nonlinearly folded at different levels in the middle of the wall. The earth pressure is higher in the middle and lower at the both top and bottom of ancient seawall. The height of actual action point of earth pressure resultant from field measuring is 0.42-0.49 times of the wall height which is upper than the theoretic calculating result. FCB is an effective unloading filled material used to decrease the pressure on the ancient seawall that it can reduce the earth pressure and overturning moment by 33.1% and 41.4% respectively comparing with undisturbed soil.