公路边坡硬岩静态爆破数值模拟研究

Numerical Simulation Study on Static Blasting of Hard Rock on Highway Slopes

边坡硬岩开挖工程中,静态爆破是最常用的破岩方法之一。结合G344东灵线栾川秋扒至三川皮皮岭段边坡开挖工程,采用了液压劈裂棒破岩方法。首先进行了岩石静力学试验,获取岩石基本物理与力学参数。利用LS-DYNA软件建立数值模型,优化劈裂棒布孔参数。最后,研究了预制节理条件下的静态裂纹扩展规律,充分考虑了节理数量、长度、位置和厚度对岩体破坏的影响。数值结果表明:完整岩体静态爆破时,最佳孔间距为90cm。预制节理条件下,岩体破坏更加容易,破碎程度更高。节理厚度对于岩石劈裂的影响不明显,而节理数量的增加显著增强了岩体的破碎效果。节理长度和节理位置的改变,影响了致裂孔产生裂纹的模式,增强了裂纹扩展的长度。

Static blasting is one of the most commonly used rock-breaking methods in slope hard rock excavation projects.Combined with G344 Dongling Line Luanchuan Qiuba to Sanchuan Pipiling section slope excavation project,hydraulic splitter bar rock-breaking method was adopted.Firstly,the rock static test was carried out to obtain the basic physical and mechanical parameters of the rock.LS-DYNA software was used to establish a numerical model to optimize the parameters of splitter bar distribution.Finally,the static crack extension law under the condition of prefabricated joints was studied,and the influence of the number,length,position and thickness of the joints on the destruction of the rock body was fully considered.The numerical results show that the optimal hole spacing is 90cm for static blasting of intact rock body.The rock body destruction is easier and the degree of fragmentation is higher under prefabricated jointing conditions.The effect of joint height on rock splitting was not significant,while the increase in the number of joints significantly enhanced the fragmentation of the rock mass.Changes in the length of joints and the location of joints affected the pattern of cracks produced by the fracturing holes and enhanced the length of crack extension.