【作者】 王光勇；

【导师】 顾金才；

【作者基本信息】 中国科学技术大学 ， 工程安全与防护技术， 2009， 博士

【摘要】 在现代战争中,随着科学技术的发展,常规钻地武器的精度越来越高,钻地越来越深,更为重要的是电子技术越来越成熟,许多防护工程面临直接命中打击的威胁。因此,通过研究常规钻地武器对锚固洞室侵彻爆炸作用,开展如何提高锚固洞室抗爆能力技术措施研究,对提高防护工程防护能力具有重要的现实意义和战略意义。本文主要是利用地质力学模型试验,并结合数值模拟分析及理论分析研究了提高锚固洞室抗爆能力的技术措施和有关力学问题,主要研究成果如下:(1)根据岩土工程抗爆试验研究实际需求,研制了性能优良的岩土工程抗爆结构模型试验装置;结合实际工程情况和主要假设,根据模型试验技术的相似原理,选择合理比例系数,确定材料的相似比例,选定相似材料;并从模型成型过程和测试技术等方面,确保了抗爆模型试验成功。(2)通过对比锚固洞室的动态破坏形态,研究了锚杆密度、锚杆长度和长短锚杆组合形式对锚固洞室的抗爆能力影响,研究发现:锚杆密度对锚固洞室的抗爆能力影响较大,而当锚杆密度小到一定程度时,锚杆长度对阻止围岩断裂缝的生成与发展影响不大,提高锚固洞室的抗爆能力不明显;在拱脚局部加长的锚杆支护可以阻止围岩裂缝穿过加长锚杆,并明显地减轻了围岩断裂缝的开裂程度,有效地提高了锚固洞室的抗爆能力。这对寻找提高锚固洞室抗爆能力技术措施具有重要启迪作用。(3)通过抗爆模型试验,得到了爆炸荷载作用下洞室的拱顶垂直压力、洞室顶底板相对位移、洞壁表面应变、顶底板加速度波形曲线;根据所测波形的峰值,拟合得出它们与比例距离的关系曲线及公式,为洞室抗爆设计与施工提供了依据。(4)首次较系统地完成了两种超常规锚杆支护(即全锚固洞室端部加密锚杆支护和端部消波锚杆支护)洞室抗爆能力研究,通过与普通加密锚杆支护洞室的抗爆能力进行比较,证明了这两种超常规锚杆支护洞室能够明显减小顶底板相对位移,使锚固洞室围岩破坏程度大大减轻,进一步提高锚固洞室的抗爆能力。(5)取自室内模型试验尺寸及材料参数,以模型试验中部分拱顶、拱腰和侧墙锚杆的轴向应变时程曲线为基础,利用数值模拟方法研究了锚杆的动态响应及加固机理,得到了锚杆轴向应力峰值分布规律;同时,利用数值模拟研究了两种超常规锚杆支护模型的加密和消波部分弹性模量和厚度对洞室的抗爆能力影响,结果表明:①随着加密部分的弹性模量增加,拱顶位移越来越小,但变化率越来越低,建议在长锚杆中间加1～2排效果较好;锚杆端部消波模型是随着消波部分弹性模量的减小,位移越来越小,并且变化很明显,即锚杆端部钻孔面积越大,效果越明显;②两种模型的加密和消波部分随着厚度的增大,位移越来越小,但变化越来越缓慢,尤其消波部分厚度变化对提高洞室抗爆能力效果更小,为提高锚固洞室抗爆能力提供了科学指南。(6)参考模型试验,利用弹性波的函数展开法求解了爆炸应力波绕洞室的散射问题,得到了P波的入射角、频率和洞室的洞径对动应力集中及振动加速度的影响规律,为爆炸动载作用下洞室围岩的有效加固指明了方向。更多还原

【Abstract】 In modern warfare,with the development of science and technology,the normal penetrating underground weapons are developed quickly towards high precision, penetrating more deepness,especially,electronics technology is more and more proficient,so many protective projects will been attacked directly.Therefore,it is of great realistic and strategic significance to carry out the technic study on enhancing the anti-detonating capacity of the surrounding rock of protective projects when these underground openings reinforced by rockbolts are explosively penetrated.This dissertation will make use of the research methods of model experiments of geomechanics,numerical simulation and theoretical analysis to study the technology of enhancing anti-detonating capacity of underground opening reinforced by rockbolts and related mechanics.The main achievements are as follows:(1) According to the requirements of geotechnical engineering anti-explosion reinforcement model test,the excellent performance model test apparatus for anti-explosion structures in rock and soil engineering is designed.Based on similarity principle of model experiment techniques,considering the practical application and main assumptions,firstly,proportional coefficients are selected properly,then, simulative ratios of the materials are calculated,and lastly simulative materials are determined.At the same time,the process of model confectioning and measuring and testing techniques are represented.These conditions ensure model tests successfully.(2) Through anti-explosion reinforcement model test,the effects of density, lengh and long-short forms of rockbolts on anti-detonating capacity were explored. Some conclusions are drawn from the model test results.The anchor density can prevent crack extension,only when anchor spacing is to a certain density,it just prevents cracks from extending into the reinforced region,but the augmentation of anchor length has no control effects to prevent crack extension in wall rock.Local and dense lengthening anchors in underground opening spandrel can prevent or interdict cracks from extending in wall rock and reduce cracks.These researches have enlightened effects on enhancing anti-detonating capacity of underground openings reinforced by rockbolts. (3)Based on anti-explosion reinforcement model test,the wave curves of vertical stress,the relative roof-to-floor displacement,surface strain of underground opening wall and accelerations of roof-to-floor and sidewall were obtained. According to peak value of the wave curves,the relationship between vertical stress, the relative roof-to-floor displacement,surface strain of underground opening wall and accelerations of roof-to-floor and sidewall and scale distance were fit,which provides basis for design and construction.(4)By comparing to the anti-detonating capacity of the underground opening which is reinforced by common dense rockbolts,the anti-detonating capacities of two kinds of supernormal rockbolts supporting were firstly studied completely.The results show that the relative roof-to-floor displacement of two the underground opening which is reinforced by supernormal rockbolts supporting can be reduced significantly,and the their surrounding rocks are damaged lightly,which shows the two underground openings can enhance the anti-detonating capacity.(5) Based on the size of model test and parameters of model materials, considering partial axial strain temporal curves of the test on vault,hance and rib, dynamic response and reinforcement mechanics of rockbolts was studied with numerical analysis,and the axial stress distribution of rock bolts was obtained.At the same time,the effects of elastic module and thickness of the dense part and weakened part on the anti-detonating capacity were studied.The study indicates that firstly, displacement of underground openings arch vault decreases with the increasing of elastic module of the dense part,and displacement of underground openings arch vault is reduced significantly with the decreasing of elastic module of the weakened part,secondly,with the increasing of thickness of the dense part and weakened part, displacement of underground openings arch vault does not decrease significantly, especially the weakened part.It is a scientific guide to enhance the anti-detonating capacity of the underground opening.(6)The wave function expansion method was used to analyzes scattering on the interaction of explosive stress waves and the underground opening,and elicited the influences of such factors as an angle of incidence,the frequency of incident explosive stress wave and the radius of the underground opening,which points the way of reinforcing the underground opening effectively.更多还原