定水头注水引起的含水层水平运动和应变

基于含水层固体颗粒与孔隙水不可压缩的假设 ,本文导出了单井注水情况下泰斯承压含水层水平运动速度与水头之间的基本关系式。然后利用注水井壁处的应力、应变边界条件 ,进一步导出了单井定水头注水引起的泰斯承压含水层水平运动速度、位移和应变解析表达式。该水平位移与应变由两部分组成 :一部分为由注水压力本身引起的经典弹性力学解项 ,它仅随半径而变化 ,与注水时间无关 ;另一部分为由地下水头变化引起的水动力学位移和应变解项。其中 ,含水层水动力学水平位移随时间加长呈指数增长特征 ,水动力学径向应变则表现为近井处拉张、远井处挤压的分区特征 ,且近井拉张区随时间加长逐渐向外扩展。单井注水含水层水动力学水平位移、应变解的导出 ,完善和发展了单孔内压经典弹性平面力学问题解     

饱和软黏土动力学特性循环扭剪试验研究

以饱和软黏土的循环扭剪试验研究为基础,阐明不固结不排水条件下饱和软黏土的动力学特性。在循环扭剪和循环三轴两种不同试验应力状态下,通过研究不同围压和不同静、动应力组合下饱和软黏土的应力等效破坏关系和应变等效破坏关系,提出在循环荷载作用下饱和软黏土的循环破坏同样遵循Mises屈服准则,且在Mises屈服准则下,饱和软黏土的循环强度趋于不变量。循环破坏的过程可以等效为一种拟静力弹塑性循环蠕变,建立了饱和软黏土循环累积变形随静荷载、循环荷载以及循环破坏振次之间的关系式。上述结论分别从应力和变形两个方面阐述饱和软黏土的动力学特性,与试验应力状态和围压无关,可以推广到一般应力状态下。     

Effect of Cyclic Loading Frequency on Undrained Behaviors of Undisturbed Marine Clay

Based on a series of cyclic triaxial tests, the effect of cyclic frequency on the undrained behaviors of undisturbed marine clay is investigated. For a given dynamic stress ratio, the accumulated pore water pressure and dynamic strain increase with the number of cycles. There exists a threshold value for beth the accumulated pore water pressure and dynamic strain, below which the effect of cyclic frequency is very small, but above which the accumulated pore water pressure and dynamic strain increase intensely with the decrease of cyclic frequency for a given number of cycles. The dynamic strength increases with the increase of cyclic frequency, whereas the effect of cyclic frequency on it gradually diminishes to zero when the number of cycles is large enough, and the dynamic strengths at different frequencies tend to the same limiting minimum dynamic strength. The test results demonstrate that the reasons for the frequency effect on the undrained soil behaviors are beth the creep effect induced by the loading rate and the decrease of sample effective confining pressure caused by the accumulated pore water pressure.     

Integration of local–global upscaling and grid adaptivity for simulation of subsurface flow in heterogeneous formations

We propose a methodology, called multilevel local–global (MLLG) upscaling, for generating accurate upscaled models of permeabilities or transmissibilities for flow simulation on adapted grids in heterogeneous subsurface formations. The method generates an initial adapted grid based on the given fine-scale reservoir heterogeneity and potential flow paths. It then applies local–global (LG) upscaling for permeability or transmissibility [7], along with adaptivity, in an iterative manner. In each iteration of MLLG, the grid can be adapted where needed to reduce flow solver and upscaling errors. The adaptivity is controlled with a flow-based indicator. The iterative process is continued until consistency between the global solve on the adapted grid and the local solves is obtained. While each application of LG upscaling is also an iterative process, this inner iteration generally takes only one or two iterations to converge. Furthermore, the number of outer iterations is bounded above, and hence, the computational costs of this approach are low. We design a new flow-based weighting of transmissibility values in LG upscaling that significantly improves the accuracy of LG and MLLG over traditional local transmissibility calculations. For highly heterogeneous (e.g., channelized) systems, the integration of grid adaptivity and LG upscaling is shown to consistently provide more accurate coarse-scale models for global flow, relative to reference fine-scale results, than do existing upscaling techniques applied to uniform grids of similar densities. Another attractive property of the integration of upscaling and adaptivity is that process dependency is strongly reduced, that is, the approach computes accurate global flow results also for flows driven by boundary conditions different from the generic boundary conditions used to compute the upscaled parameters. The method is demonstrated on Cartesian cell-based anisotropic refinement (CCAR) grids, but it can be applied to other adaptation strategies for structured grids and extended to unstructured grids.     

Direct shear tests on Mexico City clay with reference to friction pile behaviour

Summary This paper presents results of static and cyclic direct shear tests performed on undisturbed and remoulded samples of Mexico City clays, including results of soil-on-interface tests. Experiments show that the static adhesion coefficient depends on the soils' liquidity index and that it diminishes due to the effect of repeated dynamic loads. Dynamic overstrength effects were not apparent, as has been observed when testing this clay in other apparatus. Interface strength in remoulded clays is initially less than half the strength of interfaces with undisturbed materials but it increases with time. At least in the materials tested in this research, it did not equal the strength of interfaces with undisturbed materials. Correction factors derived from experimental data can be used to modify the adhesion coefficient to account for dynamic and remoulding effects.     

硫铅酸盐“S”型瞬凝水泥干法护壁堵漏技术研究

介绍了硫铝酸盐“Ｓ”型瞬凝水泥干法者漏时使用的配方,阐述了输送工具和扫孔钻具的设计以及灌注工艺技术。     

Performance of Mortar and Chemical Grout Injection into Surrounding Soil When Slurry Pipe-jacking Method is Used

Small-diameter shallow tunnels are often being built by using the slurry pipe-jacking method. This system involves the pushing or thrusting of a drivage machine and concrete pipes into the ground. Chemical grout injection into the surrounding soil around the tunnel is carried out after the drivage and pushing processes are finished. The purpose of the chemical grout injection is to maintain permanent stability of the surrounding soil. However, the behavior of the chemical grouting material in the surrounding soil around the tunnel and the amount of optimum injection is not clearly understood. From these points of view, this paper discusses the performance of the chemical grouting material, when it is injected into the surrounding soil around the tunnel, by means of 2-D Eulerian–Lagrangian seepage analysis. Moreover, the effectiveness of the chemical grout injection was evaluated by using the non-linear finite element method. This investigation show when the range of the grouted zone is designed; it is necessary that the relationship between Young’s modulus of the soil/grouted zone and the confining stress be taken into consideration in order to establish effective, economical and safe chemical grout injection system. Understanding the performance of the seepage/dispersion behavior of the chemical grout and the characteristics of soil/ grouted zone is also important.     

渤南洼陷罗151块火成岩油藏特征及开发对策

罗151块火成岩油藏是近年在济阳坳陷发现的中型油藏，油藏埋深3150m；在研究罗151井区火成岩成因、侵入期次、岩相学及储层非均质性的基础上，建立了火成岩储层概念模型，划分出角岩微孔隙型油藏及辉绿岩溶蚀孔隙-裂缝型油藏两个类型，纵向上分为4个带，平面上分为3个区；预测了火成岩储层发育的有利部位；部署了合理的开发井网，钻探后，完钻新井14口，平均单井日产油27t，取得了显著效果；火成岩油藏初期产能高，产量递减快，弹性产率低，依靠天然能量开采，最终采收率只有14．1％，可以进行注水开发，注水效果较好。     

注水煤体应力能 V-f 转化与释放机理研究

文章分析了在煤层注水湿润后煤体弹性能的转化与消耗过程，给出在湿润状态下能量由体变弹性能向形变弹性能转化进而自耗释放的理论模型。指出在坚硬干燥煤体中，注水后在水压力和毛细力的切割作用下，裂隙大量扩展，丰富了自由裂隙，产生更多的裂隙启发(裂隙切口)，使原来近似的刚性煤体变成由裂隙分割的块体组成的组合体或半组合体。裂隙中水的粘滞作用及水分子吸附力使块体问粘性结合、刚度降低、形变增大。煤体形变弹性能自身消耗释放的形式有3种：产生剪应力导致自由裂隙问错动摩擦；强度降低，使裂隙启发被劈裂成自由裂隙；湿润煤体蠕变性增强，产生整体性移动作功。初步给出能量消耗的量化表达式。通过这一理论，能建立煤层注水湿润度与冲击地压灾害发生的更直接的关系，使进一步量化该关系成为可能。从更深层次解释煤层注水防治冲击地压的机理。     

铅橡胶复合阻尼器的性能试验研究

介绍作者提出的铅橡胶复合阻尼器的构造与耗能原理，通过不同形状，不同大小铅心的8个铅橡胶复合阻尼器的循环荷载试验，研究了频率、应变幅值、循环次数、铅芯直径、竖向压力等对铅橡胶复合阻尼器的影响规律。研究结果表明，铅橡胶复合阻尼器工作性能稳定，耗能性能和抗疲劳性能好。