隧道周边孔差异化爆破作用机理及试验研究  

Mechanism and Experiment Research of Tunnel Peripheral Hole Differential Blasting

作　　者：康永全 孟海利 郭云龙 孙崔源 薛里 孙鹏昌 KANG Yongquan;MENG Haili;GUO Yunlong;SUN Cuiyuan;XUE Li;SUN Pengchang(Railway Engineering Research Institute,China Academy of Railway Sciences Corporation Limited,Beijing 100081,China)

机构地区：[1]中国铁道科学研究院集团有限公司铁道建筑研究所,北京100081

出　　处：《铁道建筑》2022年第7期114-117,共4页Railway Engineering

基　　金：中国铁道科学研究院集团有限公司基金(2021YJ066)。

摘　　要：为了降低隧道爆破损伤,基于应力波透射、反射理论,利用高分子聚氨酯泡沫材料作为保留岩体防冲材料,提出隧道周边孔差异化爆破装药结构。经理论计算,光面护壁爆破开挖侧孔壁压力是护壁侧的3.4倍,强大的压力差导致贯穿裂纹定向扩展,裂纹长度是光面爆破的1.1倍;光面护壁爆破开挖侧、护壁侧孔壁压力分别为光面爆破的174%、51%,实现了周边孔破碎和保护的差异化。经过基于声波检测技术的围岩爆破损伤试验,光面护壁爆破松动圈厚度比光面爆破降低35.9%;孔深在90 cm以内时光面爆破岩体的损伤度普遍大于光面护壁爆破,验证了光面护壁爆破对保留岩体的有效保护作用。In order to reduce the damage of tunnel blasting,based on the theory of stress wave transmission and reflection,using polymer polyurethane foam material as the anti-impact material to retain the rock mass,a differential blasting charge structure of peripheral holes was proposed. Through theoretical calculation,the hole wall pressure on the excavation side of smooth blasting with borehole wall protection is 3.4 times that of the wall protection side,and the strong pressure difference leads to the directional propagation of the through crack,and the crack length is 1.1 times that of smooth blasting. The hole wall pressure of the excavation side and the protection side of the smooth blasting with borehole wall protection is 174% and 51% that of the smooth blasting respectively,which realizes the differentiation of peripheral hole crushing and protection. Through the blasting damage test of surrounding rock based on acoustic detection technology,the thickness of loose ring of smooth blasting with borehole wall protection is 35.9% lower than that of smooth blasting. When the hole depth is less than 90 cm,the damage degree of rock mass by smooth blasting is generally greater than that by smooth blasting with borehole wall protection,which verifies the effective protection effect of smooth blasting with borehole wall protection on retained rock mass.

关 键 词：隧道 差异化爆破 现场试验 周边孔 爆破机理 装药结构 声波测试 孔壁压力 

分 类 号：U455.41[建筑科学—桥梁与隧道工程]