天水市岩土体剪切波速与埋深的变化关系

Relationship between shear wave velocity and depth of soils and rocks in Tianshui City

本文应用数理统计方法分析了天水市1 294组不同类型岩土体的剪切波速数据。结果显示,不同类型岩土体的剪切波速值随深度或风化程度不同均具有较大的变化区间;任一类型岩土体的剪切波速分布呈现出正态分布特征,其峰值区间和优势区间可以很好地反映岩土体的物理性状;松散堆积类岩土体(如:粉土、粉质粘土、卵石和圆砾等)的剪切波速与深度具有很好的相关性,可用二次函数和幂函数表达;同一类型成岩体(如:泥岩、砂岩和砾岩等)的剪切波速变化主要受岩体的裂隙发育和风化程度影响,与深度的相关性较小。

In this paper,1294 groups of shear wave velocities( Vs) of soils and rocks in Tianshui city were analyzed by the method of mathematical statistics. It is shown that the Vsof any kinks of soils and rocks have large variation range,changing with the depth of soil and the weathering degree of rock; Vsof each kinds of soils and rocks generally have the characteristics of normal distribution,furthermore,the Vsat the peak or dominance ranges of normal distribution could show the physical behavior of soils and rocks. From the relationships between Vsand depth of different soils and rocks,it can be seen that Vsof such loose deposits as silt,clayey silt,rounded gravel and gravel cobble have good correlation with depth,which can be expressed by quadratic or power functions,while Vsof base rocks like mud rock,sandstone and breccia,which are mainly influenced by weathering degree,have weak relation with depth.