顶爆条件下全长黏结式锚索的受力研究
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摘要
采用数值计算的方法,对在洞室拱顶上方爆炸荷载作用下的全长黏结式锚索的受力变化进行了研究。结果表明,顶爆条件下围岩变形的复杂性使得锚索受力变化也极为复杂。在爆炸波传播的前期,锚索受力变化最为剧烈,由整根锚索轴力受拉转变为整根受压,最大压轴力在锚索根部;锚索剪力由在锚索根部附近有负剪力和在锚索头部有正剪力转变为整根锚索均受负剪力,最大剪力峰值产生在锚索根部附近。在爆炸波传播后期,锚索头部附近拉轴力值和范围快速增大,锚索根部附近最大压轴力值和范围快速减小;锚索根部负剪力峰值不断减小,锚索头部临近洞壁岩体内锚索正剪力值和范围不断增大。在顶爆条件下,注浆体与孔壁间的剪力和锚索轴力均较大,为避免锚索轴力过大,以及注浆体与孔壁间抗剪力不足而发生锚索从孔内产生向洞内的移动,甚至被射出,失去加固围岩的能力,需施加小的预应力值和采取措施来增大锚索孔孔壁与注浆体之间的摩阻力。
The stress state of full-length bonding anchor wire located in arch crown under top explosion condition is investigated by numerical method. The results show that complex changes of rock deformation lead to complex stress state.During propagation of blast wave,the stress state varies widely: the axial tension stress state in full length turns to pressure stress state in overall length,and the maximal pressure axial force lies in root; the negative shear stress state in root and positive shear stress state turn to negative shear stress state in full length,and the maximal shear force lies in root.During the propagation of secondary blast wave,value of axial tension force and scope in head increase quickly,the axial pressure force value and scope in root decrease quickly at the same time; value of the negative shear force peak in root decrease continuously,and the positive shear force value and scope in head increase continuously. Under crown top explosion condition,shear force between injected body and rock wall of hole and axial force are high. To control the stress under the threshold value,and avoid loss of reinforcement of the anchor,the applied prestress must maintain low,and the effective methods must be adopted to increase the frictional resistance between injected body and rock wall of hole.
The stress state of full-length bonding anchor wire located in arch crown under top explosion condition is investigated by numerical method. The results show that complex changes of rock deformation lead to complex stress state.During propagation of blast wave,the stress state varies widely: the axial tension stress state in full length turns to pressure stress state in overall length,and the maximal pressure axial force lies in root; the negative shear stress state in root and positive shear stress state turn to negative shear stress state in full length,and the maximal shear force lies in root.During the propagation of secondary blast wave,value of axial tension force and scope in head increase quickly,the axial pressure force value and scope in root decrease quickly at the same time; value of the negative shear force peak in root decrease continuously,and the positive shear force value and scope in head increase continuously. Under crown top explosion condition,shear force between injected body and rock wall of hole and axial force are high. To control the stress under the threshold value,and avoid loss of reinforcement of the anchor,the applied prestress must maintain low,and the effective methods must be adopted to increase the frictional resistance between injected body and rock wall of hole.
引文
[1]王浩,陈峰,柳墩利,等.动荷载作用下边坡锚固系统合理设计探讨[J].防灾减灾工程学报,2009,29(6):690-695.
[2]单仁亮,周纪军,夏宇,等.爆炸荷载下锚杆动态响应试验研究[J].岩石力学与工程学报,2011,30(8):1540-1546.
[3]张云,刘开运.近区爆破对锚固设施的影响研究[J].水力发电,1996(8):23-26.
[4]李宁,张西前,于冲.爆破应力波对边坡预应力锚索的动力影响[J].岩石力学与工程学报,2007,26(增1):2593-2600.
[5]陆遐龄.岩石高边坡爆破开挖对锚固设施的影响[J].爆破,2000,17(增1):147-151.
[6]顾金才,陈安敏,徐景茂,等.在爆炸荷载条件下锚固洞室破坏形态对比试验研究[J].岩石力学与工程学报,2008,27(7):1315-1320.
[7]张向阳,陈安敏,徐景茂,等.不同锚杆锚固方式加固洞室抗爆能力研究[J].施工技术,2017,46(增):127-130.
[8]徐景茂,顾金才,陈安敏,等.爆炸平面波作用下大跨度洞室稳定性模型试验研究[J].岩土力学,2013,34(增1):47-53.
[9]明治清,顾金才,张向阳,等.锚杆垫板形式对洞室抗爆效果的影响试验研究[J].岩土力学,2012,33(10):2991-2995.
[10]王光勇,顾金才,陈安敏,等.锚固洞室在顶爆作用下破坏形式及破坏过程研究[J].岩土工程学报,2015,37(8):1381-1389.
[11]徐干成,顾金才,袁伟泽,等.洞室围岩交叉锚固结构抗爆性能模型试验研究[J].地下空间与工程学报,2014,10(5):1078-1085.
[12] Ana I,Andy S,Richard D N,etal. The influence of load on the frequency response of rock bolt anchorage[J],Advances in Engineering Software,2003,34(12):697-705.
该文曾在中国土木工程学会防护工程分会第十五次学术年会暨首届国防工程科技论坛交流,修改后在本刊正式发表。
[2]单仁亮,周纪军,夏宇,等.爆炸荷载下锚杆动态响应试验研究[J].岩石力学与工程学报,2011,30(8):1540-1546.
[3]张云,刘开运.近区爆破对锚固设施的影响研究[J].水力发电,1996(8):23-26.
[4]李宁,张西前,于冲.爆破应力波对边坡预应力锚索的动力影响[J].岩石力学与工程学报,2007,26(增1):2593-2600.
[5]陆遐龄.岩石高边坡爆破开挖对锚固设施的影响[J].爆破,2000,17(增1):147-151.
[6]顾金才,陈安敏,徐景茂,等.在爆炸荷载条件下锚固洞室破坏形态对比试验研究[J].岩石力学与工程学报,2008,27(7):1315-1320.
[7]张向阳,陈安敏,徐景茂,等.不同锚杆锚固方式加固洞室抗爆能力研究[J].施工技术,2017,46(增):127-130.
[8]徐景茂,顾金才,陈安敏,等.爆炸平面波作用下大跨度洞室稳定性模型试验研究[J].岩土力学,2013,34(增1):47-53.
[9]明治清,顾金才,张向阳,等.锚杆垫板形式对洞室抗爆效果的影响试验研究[J].岩土力学,2012,33(10):2991-2995.
[10]王光勇,顾金才,陈安敏,等.锚固洞室在顶爆作用下破坏形式及破坏过程研究[J].岩土工程学报,2015,37(8):1381-1389.
[11]徐干成,顾金才,袁伟泽,等.洞室围岩交叉锚固结构抗爆性能模型试验研究[J].地下空间与工程学报,2014,10(5):1078-1085.
[12] Ana I,Andy S,Richard D N,etal. The influence of load on the frequency response of rock bolt anchorage[J],Advances in Engineering Software,2003,34(12):697-705.
该文曾在中国土木工程学会防护工程分会第十五次学术年会暨首届国防工程科技论坛交流,修改后在本刊正式发表。