摘要
为研究多因素影响下大跨度地下硐室的抗爆稳定性,以模型试验为基础,利用FLAC^(3D)软件进行模拟,并改变爆炸强度、爆源位置、硐室跨度等参数,获得了不同条件下硐室围岩及衬砌结构应力、位移以及塑性区的变化规律。研究表明:爆炸施加之后,应力波自爆心呈球面向四周传播,传播过程中强度快速衰减,传播到地表和硐室自由面处发生反射,反射拉伸波使附近围岩受拉屈服,产生“层裂”现象,硐室两侧出现“八字形”裂纹;爆炸强度增加后,测点应力值及拱顶变形量增加,硐室上方的受拉区域及塑性区变大,甚至会连成一片,此时硐室可能会塌落;硐室跨度增加后,各测点应力值变化较小,拱顶变形量显著增加,抗爆性能变差;相同的爆炸强度下,顶爆作用的破坏效应最严重,爆源越偏离硐室,测点应力值、硐室变形及塑性区越小。增加硐室埋深、进行地表伪装可减轻爆炸破坏效应,加大衬砌结构强度、对拱顶拱脚进行锚固可增强硐室稳定性。该研究可为地下工程的设计和防护提供一定的借鉴。
In order to study the anti-explosion stability of a long-span underground chamber under the influence of multiple factors,simulation using FLAC3D,based on model tests,was conducted by changing the parameters of explosion strength,explosion source location and chamber span,so that to obtain the variation laws of stress,displacement and plastic zone of the surrounding rock and lining structure of the chamber under different conditions.The research results show that the stress wave propagates in a spherical form from the explosion center.In the process of propagation,the strength of the stress wave rapidly attenuates,and the reflection occurs when the wave spreads to the earth's surface and the free surface of the chamber.The reflected tensile wave makes the surrounding rock damaged,producing the phenomenon of"spalling",and splayed cracks appear on both sides of the chamber.After the explosion intensity increases,the stress values of the measuring points and the deformation of the vault increase.The tensile area and plastic zone above the chamber also become larger,and even join together,which might make the chamber collapse.With the increase of the chamber span,the stress value of each measuring point changes little,while the deformation of the vault increases significantly,which results in a worse anti-explosion performance.Under the same explosion intensity,the damage effect of top explosion is the most serious.The more the explosion source deviates from the chamber,the smaller the stress values of measuring points,deformation and plastic zone of chamber are.As a practice,increasing the buried depth of the chamber and making some surface camouflage can reduce the explosion damage effect,while increasing the strength of lining structure and anchoring the arch foot and the vault can enhance the stability of the chamber.
作者
罗军洪
刘宏伟
林振荣
付安琪
蔚立元
LUO Jun-hong;LIU Hong-wei;LIN Zhen-rong;FU An-qi;YU Li-yuan(Department of Airfield Logistics Support,Air Force Logistics College,Xuzhou 221000,China;State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining and Technology,Xuzhou 221116,China)
出处
《爆破》
CSCD
北大核心
2022年第3期181-189,共9页
Blasting
基金
国家自然科学基金项目(52179118)。
关键词
大跨度地下硐室
爆炸荷载
稳定性
动力响应
数值模拟
large-span chamber
explosion load
stability
dynamic response
numerical simulation
