杨遂中

摘 要：为控制傍山公路岩石体边坡开挖后山体路基的变形，减小传统岩石体爆破开挖后对山体路基的影响，提高山体路基的强度和稳定性，通过采集施工现场花岗岩试样，分析花岗岩内部物质的介电常数，通过微波照射试验对比试验前后花岗岩破坏形态和强度弱化规律，然后运用数值模拟方法分析弱化后花岗岩的可爆性参数设计。结果表明：花岗岩内部物质的介电常数不同对微波的敏感程度不同，微波照射弱化岩石强度具有很好的控制性;微波照射后花岗岩剪切破坏强度降低，不同剪切角度破坏时的正应力和剪应力呈线性关系;微波照射后花岗岩拉伸强度降低，为达到岩石破碎并抛掷的目的，经微波照射后花岗岩在爆破参数设计时可适当减小炮孔装药量、增加炮孔间距、增大炮孔深度、采用不耦合间断装药结构等。

关键词：傍山公路;微波照射;花岗岩;爆破参数

中图分类号：TU45 文献标识码：A 文章编号：1001-5922（2021）08-0183-04

Study on Microwave Weakening Strength and Blastability of Granite along Mountainside Highway

Yang Suizhong

（ZhengZhou Road & Bridge Construction Investment Group Co.， Ltd.， ZhengZhou 450000， China）

Abstract：In order to control the deformation of the mountain roadbed after the excavation of the rock slope of the mountain road， reduce the impact of the traditional rock mass blasting and excavation on the mountain roadbed， and improve the strength and stability of the mountain roadbed， through the collection construction site granite sample， analyzing the dielectric constant of the granite material， comparing the failure form and strength weakening law of the granite before and after the test by microwave irradiation test， then use numerical simulation methods to analyze weakening of granite after blasting parameters design. The results show that different dielectric constants of granite internal material have different sensitivity to microwave， and microwave irradiation has a good control to weaken the strength of rock. The shear strength of granite decreases after microwave irradiation， and the relationship between normal stress and shear stress at different shear angles is linear. The tensile strength of granite decreases after microwave irradiation. In order to achieve the purpose of rock breaking and throwing， the blasting parameters of granite after microwave irradiation can be designed by appropriately reducing the charging amount of the hole， increasing the spacing of the hole， increasing the depth of the hole， and adopting the decoupling discontinuous charging structure.

Key words：mountain road; microwave irradiation; granite; blasting parameters

0 引言

在高速公路規划和建设过程中，山岭地区经常遇到公路傍山而行，这就需要开挖山体边坡，针对山体边坡的开挖方法有多种多样，在面对坚硬岩石体时经常采用爆破法，有些还结合爆破配合机械的开挖方法[1-3]。但是，在坚硬岩石体边坡采用爆破法开挖时容易造成一定的弊端，如岩体崩塌、欠挖后二次爆破费时费力、超挖引起的围岩体松动、爆破引起的石屑伤人伤物事故等[4-5]。为了寻求一种更好的坚硬岩石体边坡开挖方法，本文采用微波照射弱化岩石强度再爆破的施工方法[6-7]。……