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961.
基于Global CMT提供的1976-01-01~2015-12-31期间1 255个MW≥3.5地震的震源机制解,利用FMSI方法对青藏高原西部及邻区(新疆西部地区)应力场进行反演,得到区域应力场特征,并分析西昆仑断裂带及阿尔金断裂带的断层滑动趋势。结果表明,青藏高原西部及邻区的最大主压应力轴σ1整体呈NNE-SSW向,自西向东顺时针旋转;最小主压应力轴σ3整体呈NWW-SEE向。最大主压应力轴σ1倾角大小约为5°~9°,说明该地区的构造应力场以水平运动为主。西昆仑断裂带及阿尔金断裂带具有较强的滑动趋势(Ts≥0.5),说明西昆仑断裂带及阿尔金断裂带未来失稳滑动的可能性较大。 相似文献
962.
??????M8.0????????????????????С???????????????????о???????????λ????????????????????ν???ие???????????????????1??M8.0??????????????????????????????????????С????????????????????????????????????????????????42°????????????????????????????20 km??2?????????????????????????????????????10 km?????????????????С??????????????????????????????????????????????????????λ?????????7 km??3??2??14??
ML3.7?????????????????93°?????????????????????С??????????????????????????????????2???????£????????????????????????????????????????????????????????????????4??2??28??ML3.8?????????λ?????????????????????????????????????????????????????????£???????????? 相似文献
963.
Stormwater infiltration systems are a popular method for urban stormwater control. They are often designed using an assumption of one‐dimensional saturated outflow, although this is not very accurate for many typical designs where two‐dimensional (2D) flows into unsaturated soils occur. Available 2D variably saturated flow models are not commonly used for design because of their complexity and difficulties with the required boundary conditions. A purpose‐built stormwater infiltration system model was thus developed for the simulation of 2D flow from a porous storage. The model combines a soil moisture–based model for unsaturated soils with a ponded storage model and uses a wetting front‐tracking approach for saturated flows. The model represents the main physical processes while minimizing input data requirements. The model was calibrated and validated using data from laboratory 2D stormwater infiltration trench experiments. Calibrations were undertaken using five different combinations of calibration data to examine calibration data requirements. It was found that storage water levels could be satisfactorily predicted using parameters calibrated with either data from laboratory soils tests or observed water level data, whereas the prediction of soil moistures was improved through the addition of observed soil moisture data to the calibration data set. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
964.
Extreme waves caused by tsunamis and storm surges can lead to soil failures in the near‐shore region, which may have severe impact on coastal environments and communities. Multiphase flows in deformable porous media involve several coupled processes and multiple time scales, which are challenging for numerical simulations. The objective of this study is to investigate the roles of the various processes and their interactions in multiphase flows in unsaturated soils under external wave loading, via theoretical time‐scale analysis and numerical simulations. A coupled geomechanics–multiphase flow model based on conservation laws is used. Theoretical analysis based on coupled and decoupled models demonstrates that transient and steady‐state responses are governed by pore pressure diffusion and saturation front propagation, respectively, and that the two processes are essentially decoupled. Numerical simulations suggest that the compressibility of the pore fluids and the deformation of the soil skeleton are important when the transient responses of the media are of concern, while the steady‐state responses are not sensitive to these factors. The responses obtained from the fully coupled numerical simulations are explained by a simplified time‐scale analysis based on coupled and decoupled models. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
965.
966.
粉煤灰是燃煤火力发电厂的废弃物,由大小不等、结构疏松的非晶质玻璃相球形颗粒组成,其主要化学成分是铝硅酸盐,具有来源广和成本低等特点。在水热条件下,Holler和Wirsching首先利用粉煤灰与碱(NaOH或KOH)作用合成了沸石。针对油田封堵油层孔隙即改善注水井吸水效果的实际需求,在总结和吸取粉煤灰和沸石颗粒封堵油层孔隙矿场施工成功经验和不足基础上,探索了水热条件下粉煤灰部分转化为沸石的配方组成和工艺条件,研究了改性粉煤灰组成和外观结构特征,评价了改性粉煤灰的封堵效果,分析了改性粉煤灰封堵作用机理。研究结果对改善油层孔隙封堵效果、提高油田注水效率具有重要应用价值。 相似文献
967.
桂西古侵蚀沉积断面型金矿床 总被引:1,自引:0,他引:1
古侵蚀沉积间断面型金矿是桂西的主要金矿床类型.文章着重分析该类型金矿成矿地质条件,论述矿床成因及成矿机理,认为此类型金矿易采易冶,经济效益显著,建议加大开发力度. 相似文献
968.
Kinematic pile–soil interaction under vertically impinging seismic P waves is revisited through a novel continuum elastodynamic solution of the Tajimi type. The proposed model simulates the steady‐state kinematic response of a cylindrical end‐bearing pile embedded in a homogeneous viscoelastic soil stratum over a rigid base, subjected to vertically propagating harmonic compressional waves. Closed‐form solutions are obtained for the following: (i) the displacement field in the soil and along the pile; (ii) the kinematic Winkler moduli (i.e., distributed springs and dashpots) along the pile; (iii) equivalent, depth‐independent, Winkler moduli to match the motion at the pile head. The solution for displacements is expressed in terms of dimensionless transfer functions relating the motion of the pile head to the free‐field surface motion and the rock motion. It is shown that (i) a pile foundation may significantly alter (possibly amplify) the vertical seismic excitation transmitted to the base of a structure and (ii) Winkler moduli pertaining to kinematic loading differ from those for inertial loading. Simple approximate expressions for kinematic Winkler moduli are derived for use in applications. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
969.
INTRODUCTIONThetoxicityofheavymetalsreleasedintotheenvironmenthasrecentlytriggeredanumberofstudiesaimingattheremovalofmetalionsfromaqueoussolutions (FourestandVolesky ,1 997;FehrmannandPohl,1 993 ;KuyucakandVolesky,1 989) .Itwasfoundthattheaccumulationofheavymeta… 相似文献
970.
This paper presents an analysis of the rocking vibrations of a rigid cylindrical foundation embedded in poroelastic soil. The foundation is subjected to time‐harmonic rocking excitation and is perfectly bonded to the surrounding soil. The soil underlying the foundation base is represented by a homogeneous poroelastic half‐space, whereas the soil along the side of the foundation is modeled as an independent poroelastic stratum composed of a series of infinitesimally thin layers. The behavior of the soil is governed by Biot's poroelastodynamic theory. The contact surface between the foundation base and the poroelastic soil is assumed to be smooth and either fully permeable or impermeable. The dynamic interaction problem is solved by employing a simplified analytical method. Some numerical results for the nondimensional rocking dynamic impedance and nondimensional angular displacement amplitude of the foundation are presented to show the effect of nondimensional frequency of excitation, poroelastic material parameters, hydraulic boundary condition, depth ratio and mass ratio of the foundation. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献