基于原位剪切波速测试的场地土地震液化判定方法

以原位剪切波速测试判定地震液化的优势,分析了原位剪切波测试的适用设备和基于剪切波速测定对场地土地震液化的判定方法。判别场地土地震液化,通常采用室内应变法来确定最大剪切模量,给出土的动剪切模量比和阻尼比进行判断,而采用现场剪切波速法直接判断地震液化并不常见。依据广西桂林具体工程实例进行原位剪切波速试验,对场地土地震液化判定进行了分析,得到场地土地震液化剪切波波速随深度变化曲线和不同地震烈度下土层液化剪切波速临界值及其与实测剪切波速的关系,直接对场地土地震液化进行判别。

Judgment Method for Seismic Liquefaction of Site Soil Based on In-situ Shear Wave Velocity Testing

This paper, with the advantages of judgment of seismic liquefaction by in-situ shear wave velocity testing, analyzed the applicable equipment for this testing and this test based judgment method. Generally, the judgment of seismic liquefaction of site soil defines max. shear modulus by indoor strain method, and then goes on by giving dynamic shear modulus ratio and damping ratio, however, rarely conducts field shear wave velocity test for direct judgment. According to the in-situ shear wave velocity testing carried out in specific engineering example in Guilin, Guangxi, the judgment of seismic liquefaction of site soil was analyzed to get the shear wave velocity vs.depth curve, the critical value of shear wave velocity for soil liquefaction under different seismic intensity, and the relation between this critical value and the measured shear wave velocity, by which the judgment could be carried out directly.