摘要
完整锚杆系统是由完整的锚杆杆体、饱满的锚固介质以及围岩组成的有机体系。在描述锚杆低应变动力响应的数学力学模型中,将锚固介质与围岩对锚杆体的作用简化为沿杆长均匀分布的杆侧弹性系数与阻尼系数,以及均匀分布在杆底的刚度系数与阻尼系数,即锚杆系统的动力参数。它们不仅表征了锚杆锚固质量,而且体现出锚杆所处围岩的物理参数。通过建立围岩物理参数与完整锚杆系统动力参数的映射关系,可以对围岩质量进行识别。为此,建立了完整锚杆三维轴对称有限元计算模型,得到不同的围岩物理力学参数所对应的锚杆杆顶速度响应;根据完整锚杆低应变动力响应理论解和遗传算法建立了完整锚杆动力参数的识别方法;通过对不同围岩下完整锚杆的数值模拟结果的动力参数识别,建立了杆侧弹性系数与围岩变形模量之间的关系式,提出了一种基于完整锚杆动测技术的围岩质量识别方法。
Integrated anchor system contains integrated bolt,full cement grouting and surrounding rock.In low strain dynamic response of bolt model,the action of cement grouting and surrounding rock on bolt can be considered as elastic and damping coefficients which distribute uniformly along bolt and stiffness and damping coefficients which distribute uniformly on the bottom section of it.These coefficients,named dynamic parameters,present anchorage quality,mechanical behaviors of surrounding rock are also presented.Based on the relationship between dynamic parameters of bolt system and physico-mechanical parameters of surrounding rock,the quality of surrounding rock can be identified.Three-dimensional axisymmetric calculation model is established by using finite element analysis.The velocity responses of bolt’s top with different physico-mechanical parameters of surrounding rock are obtained.A method to identify the dynamic parameters of integrated anchor system is established based on theoretical solution of integrated bolt’s dynamic response and genetic algorithm.The dynamic parameters of integrated bolt with different physico-mechanical parameters of surrounding rock are acquired;and the relation between bolt-side elastic coefficient and surrounding rock’s modulus of deformation is established.A method to identify the quality of surrounding rock through dynamic testing based on integrated anchor system is put forward.
引文
[1]刘明贵,张杰,柴华友.敲击–回波法中传感器影响的LTI系统理论分析[J].岩石力学与工程学报,2003,22(10):1689-1694.LIU Ming-gui,ZHANG Jie,CHAI Hua-you.Influence analysis of transducer in impact-echo method based on LTI system theory[J].Chinese Journal of Rock Mechanics and Engineering,2003,22(10):1689-1694.
[2]刘海峰,杨维武,李义.锚杆锚固质量动测法底端反射显现规律研究[J].辽宁工程技术大学学报,2004,23(1):41-43.LIU Hai-feng,YANG Wei-wu,LI Yi.Laboratory study on occurrence of bottom reflection by dynamical test about rock bolt bonding integrity[J].Journal of Liaoning Technical University,2004,23(1):41-43.
[3]王建宇,牟瑞芳.按共同变形原理计算地锚工程中粘结型锚头内力[C]//岩土锚固新技术,北京:人民交通出版社,1998.
[4]张永兴,许明.岩土锚固系统质量智能诊断理论与应用[M].北京:中国建筑工业出版社,2002.
[5]许明,张永兴,阴可.锚杆极限承载力的人工神经网络预测[J].岩石力学与工程学报,2002,21(5):755-758.XU Ming,ZHANG Yong-xing,YIN Ke.Prediction of limit bearing capacity of bolt using artificial neural networks[J].Chinese Journal of Rock Mechanics and Engineering,2002,2l(5):755-758.
[6]许明,张永兴.锚固系统的质量管理与检测技术研究[J].重庆建筑大学学报,2002,24(1):29-33.XU Ming,ZHANG Yong-xing.Study of quality management and inspection technology of anchorage system[J].Journal of Chongqing Jianzhu University,2002,24(1):29-33.
[7]许明,张永兴.锚杆低应变动测的数值研究[J].岩石力学与工程学报,2003,22(9):1538-1541.XU Ming,ZHANG Yong-xing.Numerical study of low strain dynamic test for bolt[J].Chinese Journal of Rock Mechanics and Engineering,2003,22(9):1538-1541.
[8]许明,张永兴,阴可.某隧道锚杆完整性的无损检测方法[J].土木工程学报,2004,37(5):78-80.XU Ming,ZHANG Yong-xing,YIN Ke.Study on nondestructive detection of bolts′integrality in a tunnel[J].China Civil Engineering Journal,2004,37(5):78-80.
[9]陈建功,张永兴,李英民.完整锚杆低应变动力响应问题的半解析解及分析[J].世界地震工程,2004,20(3):56-61.CHEN Jian-gong,ZHANG Yong-xing,LI Ying-ming.Semi-analytical solution to small strain dynamic response of integrate anchor bar and its analysis[J].World Earthquake Engineering,2004,20(3):56-61.
[10]陈建功,张永兴.完整锚杆纵向振动问题的求解与分析[J].地下空间,2003,23(3):268-271.CHEN Jian-gong,ZHANG Yong-xing.Solution and analysis for the longitudinal vibration of integrated anchor bar[J].Underground Space,2003,23(3):268-271.
[11]张永兴,陈建功.缺陷锚杆振动问题的数学模型及其求解[J].地下空间与工程学报,2005,1(1):62-66.ZHANG Yong-xing,CHEN Jian-gong.Model for longitudinal vibration of defective anchor bar and its solution[J].Chinese Journal of Underground Space and Engineering,2005,1(1):62-66.
[12]CHEN J G,ZHANG Y X.Solution and analysis on low strain longitudinal dynamic response of anchor bar-surrounding rock system[C]//Recent Development of Geotechnical and Geo-environmental Engineering in Asia,Dalian:Dalian University of Technology Press,2006.