Numerical Simulation of Magnetic Reconnection Driven by the Laser Helmholtz Capacitor-coil Targets     

XU Shan-shan  MEI Zhi-xing  ZHONG Jia-yong  LIN Jun 《Chinese Astronomy and Astrophysics》2021,45(2):131-146

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How soil texture,channel shape and cross-sectional area affect moisture dynamics and water loss in irrigation channels     

Zhifan Mu  Tianxiao Li  Dong Liu  Qiang Fu  Renjie Hou  Qinglin Li  Yi Ji  Song Cui  Mo Li 《水文研究》2021,35(4):e14155

To enhance the utilization efficiency of farmland irrigation water and reduce the leakage of water conveyance channels, the leakage process of channels was simulated dynamically. The simulated results were compared with data measured in laboratory experiments, and the performance of the model was evaluated. The results indicated that the simulated values of the model were consistent with the observation values, and the R² values varied between 0.91 and 0.99. In addition, based on the laboratory experiments, a water supply system (Mariotte bottles) and soil box were built using plexiglass. Three influencing factors, namely, the channel form, soil texture and channel cross-sectional area, were varied to observe and calculate the resulting cumulative infiltration amount, infiltration rate and wetting front migration distance. HYDRUS-3D software was used to solve the three-dimensional soil water movement equation under different initial conditions. The results demonstrated that the U-shaped channel was more effective than the trapezoidal channel in increasing the utilization efficiency of the water resources. A U-shaped channel with a small channel cross-sectional area should be adopted and the soil particle size should be prioritized in the construction of water conveyance channels for farmlands. The simulation results were in agreement with the observed results, which indicates that HYDRUS-3D is a reliable tool that can accurately simulate the soil moisture movement in water conveyance channels. The research results can provide a reference for the design and operation of farmland irrigation systems.  相似文献   

天然裂缝影响下的花岗岩水力裂缝扩展数值模拟     

王璜  王贵玲  岳高凡  甘浩男 《地质学报》2020,94(7):2124-2130

水力压裂技术是成功实现干热岩资源开发利用的重要手段之一，数值模拟技术能够精准预测水力裂缝扩展。针对典型花岗岩，借助黏性单元法，分别模拟了致密花岗岩和天然裂缝存在情况下的水力裂缝扩展特征，得出以下结论：致密花岗岩的水力裂缝形态单一，天然裂缝的存在增加了压裂后裂缝的复杂性；致密花岗岩水力裂缝拓展主要分为憋压和拓展两个交替往复的阶段，当存在天然裂隙时，水力压裂过程会变得复杂；天然裂缝存在时，水力裂缝的缝长和缝宽分别为致密花岗岩的5. 7倍和1. 7倍；缝网的形成需要借助复杂的压裂工艺实现。研究结果可以为增强型地热系统(EGS)储层水力刺激工作提供理论支持。  相似文献   

Response to the paper by H. Zia,B. Lecampion “Explicit versus implicit front advancing schemes for the simulation of hydraulic fracture growth” (Int. J. Numer. Anal. Methods Geomech., 2019, 43 (6), 1300–1315)     

Aleksandr Linkov 《国际地质力学数值与分析法杂志》2020,44(16):2254-2259

The response presents three comments, which (i) explain theoretical background for the success of the explicit front advancing scheme by Zia and Lecampion (comment 1), (ii) suggest possible extensions (comment 2), and (iii) pay attention on expected limitations of the scheme to be checked by the authors in numerical experiments (comment 3). The response does not intend to present novel results: it is entirely based on known results published in the references cited.  相似文献   

隧道工程地震易损性分析研究综述与展望          下载免费PDF全文

吴桥  程永志  黄超 《世界地震工程》2020,(2):191-199

易损性分析是隧道工程领域防震减灾研究的重要方法。首先,详细综述了国内外隧道地震易损性研究历史与现状;其次,归纳了国内外隧道地震易损性分析主要方法,并总结了各种方法的实际适用性;接着,提出了隧道地震易损性评估步骤,并且讨论了以数值模拟为主要手段的理论易损性曲线建立中的3个关键内容:(1)输入参数确定;(2)破坏状态分级;(3)相关不确定性参数计算;最后,指出该领域一些亟待解决的问题和未来研究发展的方向。结果表明:隧道地震易损性分析能通过考虑相关不确定性因素,反映了隧道在地震荷载作用下的性能,有利于未来的风险评估和损失估算,对基于性能的隧道抗震设计的发展具有重要意义。  相似文献   

煤层陷落柱多波地震数值模拟与成像研究     

朱广辉  韩建光  谷丙洛 《地质论评》2020,66(3):720-726

陷落柱是煤田勘探开发中常见的地质灾害体,陷落柱的精确探测一直是煤田安全生产研究的重点,单纯依靠常规纵波地震勘探技术难以满足现阶段煤田精细勘探的需求。多波地震勘探技术能够获得纵波和转换波地震资料,提供更丰富的波场信息,且转换波对于埋深较浅的小幅度构造有更高的分辨率,充分利用多分量地震资料可以有效的提高地震勘探的精度。本文将多波地震技术应用到煤层陷落柱研究中,利用数值方法对煤层陷落柱进行多波地震勘探模拟研究,采用弹性波有限差分方法对构建的陷落柱模型进行多分量正演模拟,然后分别对波场分离后的PP波和PS波地震数据进行叠前深度偏移成像测试。通过对两个小尺寸陷落柱模型进行多波地震数值试算表明,多波地震勘探技术是一种有效的煤层陷落柱探测方法,充分利用多波地震资料有利于查明煤层陷落柱构造,对陷落柱取得更好的勘探效果。  相似文献   

Fully coupled hydraulic fracture simulation using the improved element partition method     

Shujun Peng  Zhennan Zhang  Jianye Mou  Bing Zhao  Zhiyuan Liu  Jiading Wang 《国际地质力学数值与分析法杂志》2019,43(1):441-460

The improved element partition method (IEPM) is a newly developed fracture simulation approach. IEPM allows a fracture to run across an element without introducing extra degrees of freedom. It can also simulate any number of fractures in a prescribed mesh without remeshing. In this study, the IEPM is extended to hydraulic fracture simulation. First, the seepage and volumetric storage matrix of a cracked element are derived using virtual nodes (the intersection points of a crack with element edges). Subsequently, the fully coupled hydromechanical equation is derived for this cracked element. To eliminate the extra degrees of freedom (virtual nodal quantities), the water pressure and displacement of the virtual nodes are associated with their adjacent nodes through least squares interpolation. Finally, the fully coupled equation in terms of nodal quantities is obtained. The verification cases validate the method. By using this method, the field-scale hydraulic fracturing process is well simulated. The proposed approach is simple and efficient for field-scale hydraulic fracture simulation.  相似文献   

Robust numerical implementation of a 3D rate-dependent model for reservoir geomechanical simulations     

Giovanni Isotton  Pietro Teatini  Massimiliano Ferronato  Carlo Janna  Nicolò Spiezia  Stefano Mantica  Giorgio Volonte 《国际地质力学数值与分析法杂志》2019,43(18):2752-2771

A 3D elasto-plastic rate-dependent model for rock mechanics is formulated and implemented into a Finite Element (FE) numerical code. The model is based on the approach proposed by Vermeer and Neher (A soft soil model that accounts for creep. In: Proceedings of the International Symposium “Beyond 2000 in Computational Geotechnics,” pages 249-261, 1999). An original strain-driven algorithm with an Inexact Newton iterative scheme is used to compute the state variables for a given strain increment.The model is validated against laboratory measurements, checked on a simplified test case, and used to simulate land subsidence due to groundwater and hydrocarbon production. The numerical results prove computationally effective and robust, thus allowing for the use of the model on real complex geological settings.  相似文献   

Using the applied element method for modelling calcium silicate brick masonry subjected to in‐plane cyclic loading     

Daniele Malomo  Rui Pinho  Andrea Penna 《地震工程与结构动力学》2018,47(7):1610-1630

The response of calcium silicate unreinforced masonry construction to horizontal cyclic loading has recently become the focus of experimental and numerical research, given its extensive use in some areas of the world that are now exposed to induced earthquakes (eg, north of the Netherlands). To assess the seismic behaviour of such construction, a relatively wide range of modelling methodologies are available, amongst which the discrete elements approach, which takes into account the intrinsic heterogeneity of a brick‐mortar assembly, can probably be deemed as the most appropriate computational procedure. On the other hand, however, since discrete elements numerical methods are based on a discontinuum domain, often they are not able to model every stage of the structural response adequately, and because of the high computational burden required, the analysis scale should be chosen carefully. The applied element method is a relatively recent addition to the discrete elements family, with a high potential for overcoming the aforementioned limitations or difficulties. Initially conceived to model blast events and concrete structures, its use in the earthquake engineering field is, of late, increasing noticeably. In this paper, the use of the applied element method to model the in‐plane cyclic response of calcium silicate masonry walls is discussed and scrutinised, also through the comparison with experimental results of in‐plane cyclic shear‐compression tests on unreinforced masonry walls.  相似文献   

滇西北地区近年来应力场的数值模拟研究     

武永彩  李昂  唐红涛 《大地测量与地球动力学》2018,38(12):1238-1240

建立滇西北地区三维有限元地质模型，将2009~2016年GPS速度场数据作为数值模拟的位移边界条件，模拟获取该地区的构造应力场。结果表明，在楚雄至滇西北地区整体显示张性应力区；出现由“洱源鹤庆断裂-红河断裂-程海断裂”圈起的低值张性区，区域内部张性应力明显低于外部，这种张应力低值区尤其在区域四周断裂边界处，往往是地壳断裂活动的频发区；曲江断裂北端及元谋-绿汁江断裂南端出现张性应力集中区，是今后重点关注的断裂结点。  相似文献