中文摘要：

利用有限元LS-DYNA3D程序，分析深孔爆破时岩体中软弱层内的爆腔半径随软弱层厚度、倾角、炮孔直径、装药量和装药量长径比的变化规律。结果表明：软弱层厚度≥5cm时，爆腔形状近似为圆柱形；软弱层厚度不变时，爆腔半径随炮孔直径和装药量的增加呈幂函数规律增加；在相同炮孔直径和装药量条件下，爆腔半径随软弱层厚度的增加而线性增加，且增幅逐渐减小;爆腔相对半径随装药量长径比的增大而增大；爆腔半径随软弱层与炮孔轴线夹角（锐角）的减小而减小，且减幅逐渐减小，但软弱层垂直于其中性面的位移却随之增加，夹角为50^o时该位移达10cm；在装药段长度内，软弱层位置对爆腔的形状和尺寸的影响很小，爆腔半径的最大相对变化仅为1．2％。

英文摘要：

By means of LS-DYNA3D program, the change rule of the blast cavity radius inside the weak intercalation in layered rock mass under deep-hole blasting is analyzed. The change of blast cavity radius is related with the thickness and the obliquity of weak intercalation, blasthole diameter, explosive charge, and the length-diameter ratio of explosive charge. Results indicate that the blast cavity is close to the shape of a column when the thickness of weak intercalation is greater than or equal to 5 cm. At the same thickness of weak intercalation, the radius of blast cavity increases with the increment of blasthole diameter and the explosive charge, and the increase shows a power function tendency. Under the condition of the same blasthole diameter and explosive charge, the radius of blast cavity increases linearly with the increment of the thickness of weak intercalation, and the amplitude decreases gradually. The relative radius of blast cavity increases with the increment of the length-diameter ratio of explosive charge. With the decrease of the angle （sharp one） between weak intercalation and the blasthole axes, the radius of blast cavity decreases, and the decrease is little by little. At the same time, the displacement perpendicular to the neutral layer of the weak intercalation increases up to 10 cm when the angle increases to 50^o. Within the range of explosive charge length, the location of weak intercalation almost has no effect on the shape and the size of blast cavity, and the maximum relative change of the blast radius is only 1.2%.