第三系砂岩波速特性探讨及统计分析

波速测试技术作为一种简便、快捷的测试技术被广泛应用于各种工程实践中, 第三系砂岩是非常具有代表性的软岩, 对第三系砂岩波速测试的研究具有重要意义。本文以吉阳核电厂址的第三系砂岩为研究对象, 通过整理单孔波速、跨孔波速方法获得的参数, 分析半成岩岩体波速的空间分布规律及特性, 寻找波速与埋深深度、标贯动探参数之间的关系。结果表明单孔、跨孔波速测试波速值随深度增加而增加, 埋深5m以上增加幅度明显, 埋深5m以下增加趋势减缓, 平面上不同位置各孔的波速值基本一致, 说明第三系半成砂岩岩体分布较均匀。剪切波速与埋置深度线性回归拟合效果较好, 对数拟合优度在0.95以上, 精度最高, 相对可靠, 剪切波速与标贯击数之间相关性不明显, 与动探击数之间基本不相关。

STATISTICAL ANALYSIS AND RESEARCH ON WAVE VELOCITY OF THE TERTIARY SANDSTONE

Wave velocity testing technology has been widely used in various engineering as a simple, quick test technology, and the Tertiary sandstone is one of the very representative soft rocks, so it has very important implications to research on Wave velocity testing of the Tertiary sandstone. This paper took the Tertiary sandstone in Jiyang nuclear power plant as an example, analysed the spatial distribution of the semi-formed Rock's wave velocity and searched the relationship of the wave velocity with depth, SPT and CPT though organizing the data of the wave velocity gain by cross-hole wave velocity measurement and single-hole wave velocity measurement. The results shows that the wave velocity increases with depth, above the depth of 5m, the rate of increase is very significantly, and the increase rate trend slow below the depth of 5m. The wave velocity for different holes are basically the same, which indicate that the Tertiary semi-formed sandstone is uniformitarian. Shear wave velocity and depth of buried linear regression fit well; there is no significant correlation between the shear wave velocity and SPT, and the shear wave velocity and CPT are uncorrelated.