岩石爆破损伤断裂的细观机理

基于现有岩石爆破机理和岩石细观损伤力学 ,认为岩石爆破损伤断裂过程包含有爆炸应力波的初期动态损伤演化阶段和后期爆生气体作用下的准静态损伤演化阶段 ,并分别建立了这两个阶段的损伤模型和断裂准则 ,阐述了岩石爆破损伤断裂的细观理论。     

液相等离子体岩石爆破机理初步研究

建立了以NaCl溶液和高能量电容器组构成的等离子体模型试验系统 ,并将其用于岩石爆破试验。试验结果表明 :液相等离子体具有破碎介质的能力 ,试验系统是可靠的 ;与传统的炸药爆破相比 ,等离子体岩石爆破具有不产生粉尘、无炮烟、无有毒气体、无抛掷、低噪音等特点。     

建筑结构对爆破震动的响应预测

介绍了一种在爆前即能预测建筑结构对爆破震动的响应的方法。通过预测结构地基的震动波形计算结构的抗震设计反应谱 ,用动力分析法计算结构在爆破震动作用下的响应。预测结果为结构所受内力的定量数值 ,并且还可通过不同延期时间下的预测结果比较 ,为爆破设计选取最佳延期时间。实际应用表明 ,预测结构可靠。此方法可用于预测结构在爆破震动作用下的安全性。     

三角柱直眼掏槽爆破参数研究

通过对三角柱直眼掏槽爆破进行试验研究 ,认为爆破槽腔的形成过程可分成两个阶段 ,即岩石破坏阶段和破碎岩石抛出阶段 ;进而 ,依照岩石压缩破坏与剪切破坏的力学准则 ,导出三角柱直眼掏槽炮眼间距与装药系数的计算式 ;根据计算结果 ,在井下巷道工程实际应用中进行对比 ,证实了它的可靠性。     

近距侧爆情况下马蹄形隧道动态响应特点的研究

在数值模拟和动光弹试验研究的基础上 ,对马蹄形隧道在邻近爆破作用下的动态响应特点进行了分析 ,并在综合考虑入射应力波波长、隧道直径、爆源与隧道的相对距离的基础上 ,提出了隧道迎爆一侧的动应力集中因子的近似确定方法 ,为今后邻近隧道的爆破施工安全提供了有益的参考。     

相似理论在深孔梯段爆破飞石距离计算中的应用

利用相似理论 ,推导了深孔梯段爆破中飞石距离的计算公式。结合三峡工程实际统计数据的回归分析导出了公式的具体表达式 ,讨论了公式的应用条件和进一步完善的研究思路。     

A Modified SQP Method and Its Global Convergence

The sequential quadratic programming method developed by Wilson, Han andPowell may fail if the quadratic programming subproblems become infeasibleor if the associated sequence of search directions is unbounded. In [1], Hanand Burke give a modification to this method wherein the QP subproblem isaltered in a way which guarantees that the associated constraint region isnonempty and for which a robust convergence theory is established. In thispaper, we give a modification to the QP subproblem and provide a modifiedSQP method. Under some conditions, we prove that the algorithm eitherterminates at a Kuhn–Tucker point within finite steps or generates aninfinite sequence whose every cluster is a Kuhn–Tucker point.Finally, we give some numerical examples.     

爆炸破碎区域划分的模糊数学方法

本文以最大径向应力,最大剪应力和最大切向应力为主要的破碎准则,利用二元分配法分析了诸破碎准则间权的分配,采用正态函数、降正态函数和升正态函数为各个破碎准则的录属函数,由此提出了爆炸破碎的过粉碎区,初始裂缝区和纯粹拉断区划分的综合评价方法。实例证明,对于大药量或小药量爆炸,以上方法均可成立。     

An Acceleration Technique for the Augmented IIM for 3D Elliptic Interface Problems

A new fast algorithm based on the augmented immersed interface method and a fast Poisson solver is proposed to solve three dimensional elliptic interface problems with a piecewise constant but discontinuous coefficient. In the new approach, an augmented variable along the interface, often the jump in the normal derivative along the interface is introduced so that a fast Poisson solver can be utilized. Thus, the solution of the Poisson equation depends on the augmented variable which should be chosen such that the original flux jump condition is satisfied. The discretization of the flux jump condition is done by a weighted least squares interpolation using the solution at the grid points, the jump conditions, and the governing PDEs in a neighborhood of control points on the interface. The interpolation scheme is the key to the success of the augmented IIM particularly. In this paper, the key new idea is to select interpolation points along the normal direction in line with the flux jump condition. Numerical experiments show that the method maintains second order accuracy of the solution and can reduce the CPU time by 20-50%. The number of the GMRES iterations is independent of the mesh size.     

坚硬顶板爆破切顶在沿空留巷中的应用研究

当煤层上方为坚硬顶板时,在工作面回采期间容易出现大面积悬顶,导致巷旁充填体出现大变形破坏,极大威胁采煤安全.为解决这一问题,以某矿1205工作面沿空留巷为工程背景,分析了爆炸围岩裂隙范围和坚硬顶板破断特征,建立了切顶卸压围岩结构力学模型,研究表明,相邻炮孔爆炸后,炮孔间裂隙互相贯穿,降低了顶板强度,同时当切顶角为15°...