泥岩夹层对盐岩变形和破损特征的影响分析

针对我国大多数盐矿的多层盐岩地质构造特征，对含泥岩夹层盐岩、纯泥岩和纯盐岩3种岩芯试样进行单轴压缩和不同围压下三轴压缩试验研究，对比分析3种试样的变形和破坏特性。试验结果表明：泥岩夹层对盐岩体的变形和破坏特性有明显的影响，强度高于盐岩的泥岩夹层却先于盐岩出现横向拉伸破坏；此外还观察到应力-应变曲线的“应力跌落”现象。针对试验结果，利用Cosserat介质扩展理论对泥岩夹层的影响进行理论分析。分析结果表明，泥岩和盐岩力学特性上的不匹配导致二者界面附近泥岩体等效受到横向拉伸应力作用，这很好地解释试验结果，这一分析结果可对进一步进行层状盐岩体内油（气）储库洞室稳定性分析提供理论基础。     

Equivalent Mohr–Coulomb and generalized Hoek–Brown strength parameters for supported axisymmetric tunnels in plastic or brittle rock

The evaluation of equivalent Mohr–Coulomb (M–C) strength parameters to the prototype Hoek–Brown (H–B) ones for tunnels has been tackled in different ways for many years. The extension of the H–B criterion to the generalized one has made the challenge even greater. Most of the latest methods did not account for the effect of the support pressure and none gave formulae for equivalent parameters of supported or brittle rock. Here, an almost exact explicit solution for the evaluation of the critical pressure, of a tunnel in a rock mass satisfying the generalized H–B criterion, is initially investigated. Then, formulae are derived for the evaluation of equivalent parameters, of either elastoplastic or elastic–brittle plastic rock. They are based either on a best fitting procedure of the two envelopes or on the equation of selected responses of the models. Supported tunnels in equivalent M–C rock masses are then validated against those excavated in the prototype H–B rock masses.     

多功能共振柱刚性试件试验的可靠性分析

对我国自行研制的多功能共振柱试验机测试刚性试件动剪切模量的可靠性进行研究,提出了一种修正系数方法,给出了测试刚性试件时的自振和共振修正曲线。试验中,6个不同刚度试件10次自振试验和10次共振试验的频率误差最大均不超过4%,10次自振试验曲线之间的相关性也很好。比较了3种修正系数拟合模型,给出了修正曲线最佳拟合方式。对3种已知模量的刚性试件进行了自振和共振试验,采用修正曲线得到的结果与已知值的最大误差不超过10%。表明提出的修正系数方法和修正曲线可靠,新设备测试精度和稳定性良好,可用于小应变范围内硬质材料动剪切模量的实际测试。     

Elastic–brittle–plastic analysis of circular openings in Hoek–Brown media

A closed-form solution is presented in this paper for the prediction of displacements around circular openings in a brittle rock mass subject to a hydrostatic stress field. The rock mass is assumed to be governed by Hoek–Brown yield criterion and a non-associated flow rule is used. For the elastic–brittle–plastic analysis of circular openings in an infinite Hoek–Brown medium, the existing analytical solutions were found to be incorrect. The present closed-form solution is based on a theoretically consistent method and the solution does not require the use of any numerical method.The present closed-form solution was validated by using the finite element method. In the finite element analysis, the infinite boundary was simulated “exactly” by using the newly developed elastic support method. Several cases were analyzed and the present closed-form solutions for stresses and displacements were found to be in an excellent agreement with those obtained by using the finite element method.     

水射流在煤层中水平钻孔的试验研究

分析了水射流流动结构中存在的三个射流阶段和水射流作用于煤层时所具有的撞击、冲击、水楔、气蚀、剪切等破岩机理和岩石的破坏过程。深入探讨了目前有关水射流破岩的前沿问题，提议从岩石动态破碎和水射流与岩石的相互耦合作用的角度来分析水射流的破岩过程。提出了用高压水射流在煤层中钻孔的一种新方案，即采用缠绕在辊筒上的连续钢管，将水射流钻头与高压水泵连接起来，在煤层中实施连续钻孔作业，本方案自动化程度高。可加快钻孔速度。通过试验数据分析了水射流破岩距离与射流压力的非线性关系，对钻孔煤渣做了分样分析，认为水射流钻孔产生的煤渣颗粒大于普通的钻孔煤渣。研究结果表明：水射流破岩时存在一个门限压力，水射流压力和流量与破岩效率成非线性变化的相关规律，与流量相比，射流压力对破岩作用更为重要。     

基于应变的脆性岩石破坏强度研究

在三轴压缩条件下，岩石类材料的破坏具有延性破坏和脆性破坏2种类型。岩石发生破坏的机理是构成岩石的矿物颗粒之间发生相对位移。一般而言，岩石在力的作用下发生拉或剪破坏，在破坏发展过程中，哪一种破坏类型取得优势地位，岩石最终便以那种形式破坏。最大拉应变准则能够解决岩石拉破坏问题，但不能解释破裂角的存在。岩石为各向异性体，应变主轴不同于加载轴，因此，不能用加载轴上的应变来描述岩石的强度。考虑3个方向拉应变的应变强度准则能够描述岩石的强度，也能够在一定程度上描述破裂角的变化。理论分析和室内试验证实了这一结论。并且随中间主应力的升高，应变破坏准则的变化与岩石抗压强度、最大拉应变准则的变化具有相同的规律。     

福建博物院大面积干挂石材幕墙工程施工质量控制

福建博物院工程外墙大面积采用花岗石干挂石材幕墙,结合创科技示范工程和工程创优,获得良好的装修质量和装饰效果,总结出了大面积干挂石材幕墙工程施工质量控制技术。     

Uncertainty analysis of tunnel squeezing for two tunnel cases from Nepal Himalaya

Weak rocks such as shale, slate, phyllite and schist, and the rock mass of weakness/fault zones are incapable of sustaining high tangential stress. Severe tunnel squeezing is therefore common in the tectonically active Himalayan rock mass and is one of the major areas of concern regarding stability. A reliable prediction of the extent of squeezing is essential so that a strategy can be established regarding stabilizing measures and for optimizing the support well in advance (during planning and design). In this paper, a probabilistic approach to uncertainty analysis that focuses on the effect of the variations in each input parameter of squeezing is used for analyzing and predicting the extent of tunnel squeezing for two tunnel cases in Nepal; Kaligandaki “A” (completed) and Middle Marsyangdi (under construction). A semi-analytical method suggested by Hoek and Marinos [Predicting tunnel squeezing problems in weak heterogeneous rock masses. Tunnels Tunnell Int, 2000; 32(11 and 12): 45–51 and 34–36] for predicting squeezing, an empirical formula proposed by Panthi [Analysis of engineering geological uncertainties related to tunnelling in Himalayan rock mass conditions. PhD thesis, Department of Geology and Mineral Resources Engineering. Norwegian University of Science and Technology (NTNU), Norway, 2006] and the Palisade's 2002 version of @Risk statistical software program have been used for the uncertainty analysis. The analysis results for Kaligandaki indicate fairly good correlation between predicted and actually measured squeezing. The same approach has been used for predicting the degree of tunnel squeezing at Middle Marsyangdi tunnel. It is concluded that the methodology proposed in this paper has potential for predicting the squeezing of future tunnel projects in weak rock mass conditions.     

地铁浅埋暗挖法施工引起的地表沉降控制标准的统计分析

由于在地铁施工过程中不可避免地会对地层产生扰动，就必然产生不同程度的地面沉降，从而对地铁施工及周边环境的安全性产生不利的影响，例如对城市的道路、桥梁、地下管线和地面建构筑物等的安全性产生不利的影响。因此，科学合理地确定地表沉降控制指标，以减轻、消除和避免由于地表沉降产生的不利影响，是十分必要的。通过对众多工程实例的实地调研，并综合运用模糊聚类分析方法对实地调研数据进行统计分析，同时考虑工程建设的经济性，给出在目前工程条件下地表沉降控制值的建议值，这对指导地铁工程的施工有十分重要的意义。     

单层球面网壳结构的风致响应分析

讨论完全二次型组合(CQC)方法和模态加速度法在单层球面网壳结构风致响应计算中的应用,对0.1矢跨比单层球面网壳采用同步多点压力扫描技术进行了风洞试验。根据由脉动风荷载和结构模态得到的广义力功率谱,分别用CQC法和平方-总和-开方法(SRSS)计算了结构的风致响应。检查不同模态数对响应精度的影响以及模态响应分量的相关性,发现SRSS方法对这类结构并不合适,不同模态响应之间的相关性未被考虑在内。位移响应功率谱表明响应的共振分量是显著的,对某些节点甚至比背景分量更加重要。与传统的模态叠加法不同,模态加速度法中可以用剩余柔度的拟静态响应近似补偿截断的高阶模态对响应的贡献。