断层破碎带中的透镜体及透镜体力学效应初步研究

断层破碎带中的透镜体及透镜体力学效应研究在文献中不多见。但是许多断层尤其是扭性断层中的透镜体非常发育,这些透镜体往往控制断层破碎带的强度大小和变形破坏机理,是工程岩体中必须重视的工程地质力学问题。作者经研究认为:(1)透镜体类型多种;(2)透镜体周边一般具断层泥线或泥膜分布;(3)透镜体内具有节理裂隙系统;(4)透镜体周边可以当作结构面或软弱结构面看待;(5)透镜体本身可以作为一个复合结构体看待。在原位力学试验中也揭示了断层泥透镜体在原位剪切试验和单轴压缩试验中的若干力学行为,其表现是:(1)透镜体周边具有结构面力学效应;(2)断层泥透镜体控制着强度大小、变形破坏机理。     

An experimental study of the effect of the blow-in rate on the size of the flow separation region

Experimental results are presented concerning the effect of the air blow-in rate on the size of the flow separation region downstream of a rearward-facing step at different step heights. The stream function is found from the experimental velocity profiles, the streamline = 0 being taken as the boundary line. It is shown that the separation region increases as the blow-in rate is increased. Generalization of the experimental results for different blow-in rates and step heights has made it possible to obtain an analytical expression describing the location of some characteristic lines in the separation region (boundary streamline, reverse-flow boundary, line of reverse-flow maximum velocity, line of variable-velocity layer thickness, and the displacement thickness line). Velocity profiles are obtained by means of a hot-wire anemometer. Analytical expressions are written as polynomials with unknown coefficients. The results obtained may be helpful in developing techniques for the treatment of heat transfer under flow separation conditions.     

遥感技术用于固体力学实验研究的新成果

在岩石、混凝土和钢材加载直到破坏的过程中用红外和微波遥感技术进行了观测研究．发现这些材料在加载过程中其红外和微波辐射温度、红外辐射波谱及红外热像均随应力的变化而变化．材料破坏前这些变化表现出某些前兆性特征．研究表明遥感技术可作为固体力学研究的一种新手段，并可望在工程上得到应用     

Slow gas motions and the negative drag of a strongly heated spherical particle

In the slow flows of a strongly and nonuniformly heated gas, in the continuum regime (Kn → 0) thermal stresses may be present. The theory of slow nonisothermal continuum gas flows with account for thermal stresses was developed in 1969–1974. The action of the thermal stresses on the gas results in certain paradoxical effects, including the reversal of the direction of the force exerted on a spherical particle in Stokes flow. The propulsion force effect is manifested at large but finite temperature differences between the particle and the gas. This study is devoted to the thermal-stress effect on the drag of a strongly heated spherical particle traveling slowly in a gas for small Knudsen numbers (M ～ Kn → 0), small but finite Reynolds numbers (Re ≤ 1), a linear temperature dependence of the transport coefficients µ ∝ T, and large but finite temperature differences ((T _w ? T _∞ )/T _M8 ～ 1). Two different systems of equations are solved numerically: the simplified Navier-Stokes equations and the modified Navier-Stokes equations with account for the thermal stresses.     

多孔介质平板通道强迫对流中热局部非平衡时的热应力

根据微观不可压饱和多孔介质热-力-流相互作用的一般理论,在固相骨架小变形的假定下,考虑固相和流相相互作用的粘性耗散,研究了多孔介质平板通道强迫对流热局部非平衡的热应力问题.建立了问题的热-力数学模型,根据饱和多孔介质的平衡方程,在固相骨架只存在横向位移的假定下,求解了固相骨架的位移和相应的热应力,数值考察了各种物性参数对热应力分布的影响,讨论了热局部平衡模型的适用性.     

Dynamical behaviors of nonlinear viscoelastic thick plates with damage

Based on the deformation hypothesis of Timoshenko's plates and the Boltzmann's superposition principles for linear viscoelastic materials, the nonlinear equations governing the dynamical behavior of Timoshenko's viscoelastic thick plates with damage are presented. The Galerkin method is applied to simplify the set of equations. The numerical methods in nonlinear dynamics are used to solve the simplified systems. It could be seen that there are plenty of dynamical properties for dynamical systems formed by this kind of viscoelastic thick plate with damage under a transverse harmonic load. The influences of load, geometry and material parameters on the dynamical behavior of the nonlinear system are investigated in detail. At the same time, the effect of damage on the dynamical behavior of plate is also discussed.     

建筑物内火灾烟羽流和顶蓬射流诱发的空气运动盐水模拟实验研究

盐水在清水中的扩散与火灾烟气在空气中的蔓延相似，因而可用盐水的扩散来模拟火灾烟气的蔓延；同样地，由于盐水的扩散而导致的环境清水的运动也可用来模拟烟气蔓延诱发的空气运动。基于这一原理，本文用实验的方法，研究了建筑物内初起火灾产生的烟羽流和顶蓬射流所诱发的空气运动，并对走廊空气层生长规律和运动特性进行了初步的测量和分析。所得结果基本合理，对建筑物通风排烟及疏散通道设计有帮助，从而为建筑火灾环境空气的运动的实验研究开辟了新的思路，也为火灾区域模拟提供了实验依据     

天水地区断裂活动性与地质灾害的相关性研究

在对天水地区断裂活动性的实地调查和断裂带氡气含量测试的基础上,对研究区内断裂的活动性进行了分析评价分级,分析了地质灾害的发育与分布特征,研究了断裂活动性与地质灾害发育程度之间的关系。研究表明,研究区断裂活动性与地质灾害的发育程度之间有着密切的联系,断裂活动是本区地质灾害的主要影响因素之一。     

转向剂形成人工应力遮挡的实验研究及有限元分析

针对水力压裂过程中采用的人工应力遮挡控制缝高技术,通过室内物理模拟实验,在转向剂浓度一定的条件下考虑携带液与地层压差、渗流量、时间等因素,采用电测法对人工岩芯表面应变进行了测试;利用非线性有限元方法对裂缝尖端应力进行计算,研究了转向剂形成人工应力遮挡的作用效果。结果表明采用转向剂可以建立3~4MPa的人工应力遮档,对采用转向剂的压裂设计和施工参数提出了建议。