爆破作业下黄土围岩的破碎特征及响应规律OA

In loess region blasting operations,the fragmentation and compaction effects on surrounding loess sig-nificantly influence both construction quality and blast design optimization.Field blasting experiments were conducted to examine these effects,utilizing digital image processing techniques to extract cavity surface crack and clod charac-teristics for loess fragmentation analysis.Concurrent measurements of blast cavity profiles and peripheral cracks were combined with laboratory testing to determine blast-affected soil zoning boundaries.Numerical modeling was imple-mented in LS-DYNA based on field data,with explosive length variations simulating different charge weights for loess blasting scenarios.The experimental results demonstrate that the post-blast loess exhibits five distinct elliptical zones:cavity zone,crushed zone,cracked zone,compacted zone,and elastic deformation zone.Within the crushed zone,the soil develops both wide fractures and short,thin cracks,predominantly interconnected through T-shaped nodal intersections.The resulting clods primarily display irregular quadrilateral morphology with complex geometries and extensive internal cracking networks.In contrast,the cracked zone predominantly develops elongated,narrow cracks interconnected through Y-shaped nodal intersections,exhibiting irregular pentagonal and hexagonal morpholo-gies.Experimental analysis reveals a hyperbolic correlation between explosive weight and both the radial dimensions of the blast cavity and its influence range.In contrast,axial dimensions demonstrate linear proportionality to explosive mass.