Tensionless–frictionless interaction of flexible annular foundation with a transversely isotropic multi‐layered half‐space          下载免费PDF全文

Morteza Eskandari‐Ghadi  Ghasem Gorji‐Bandpey  Azizollah Ardeshir‐Behrestaghi  Seyed Masoud Nabizadeh 《国际地质力学数值与分析法杂志》2015,39(2):155-174

A transversely isotropic multi‐layered half‐space, with axis of material symmetry perpendicular to the free surface, supports a flexible either annular or solid circle foundation. The contact area of the foundation and the half‐space is considered to be both frictionless and tensionless. The foundation is assumed to be affected by a vertical static axisymmetric load. Detailed analysis of the interaction of these two systems with different thickness of layers is the target of this paper. With the use of ring load Green's functions for both the foundation and the continuum half‐space, an integral equation accompanied with some inequalities is introduced to model the complex BVP. With the incorporation of ring‐shape FEM, we are capable of capturing both regular and singular solution smoothly. The validity of the combination of the analytical and numerical method is proved with comparing the results of this paper with a number of benchmark cases of both linear and nonlinear interaction of circular and annular foundation with half‐space. Some new illustrations are presented to portray the aspect of the anisotropy and layering of the half‐space. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

One-dimensional consolidation of soil under multistage load based on continuous drainage boundary     

Yi--> Tian  Wenbing Wu  Guosheng Jiang  M. Hesham El Naggar  Guoxiong Mei  Meijuan Xu  Rongzhu Liang 《国际地质力学数值与分析法杂志》2020,44(8):1170-1183

In engineering practice, a rapid loading rate can result in ground failure when the strength of soft soils is relatively low, and a multistage loading scheme is always utilized to deal with this situation. Firstly, under a multistage load and the continuous drainage boundary, an analytical solution of excess pore-water pressure and consolidation degree is obtained by virtue of the superposition formula of excess pore-water pressure, and a more general continuous drainage boundary under arbitrary time-dependent load is developed. Then, a comparison with existing analytical solutions is conducted to verify the present solution. A preliminary attempt on applying the continuous drainage boundary into the finite element model is made, and the feasibility of the numerical model for the one-dimensional consolidation under the continuous drainage boundary is verified by comparing the results calculated by FEM with that from present analytical solution. Finally, the consolidation behavior of soil is investigated in detail for different int erface parameters or loading scheme. The results show that, in land reclamation projects, a horizontal drain should be placed close to the boundary with a smaller interface parameter to improve the consolidation efficiency. The degree of consolidation is also related to the applied time-dependent load and interface parameters.  相似文献   

Analytical solutions for advective–dispersive solute transport in double‐layered finite porous media     

Peter John Cleall 《国际地质力学数值与分析法杂志》2011,35(4):438-460

Analytical solutions for advection and dispersion of a conservative solute in a one‐dimensional double‐layered finite porous media are presented. The solutions are applicable to five scenarios that have various combinations of fixed concentration, fixed flux and zero concentration gradient conditions at the inlet and outlet boundaries that provide a wide number of options. Arbitrary initial solute concentration distributions throughout the media can be considered via explicit formulations or numerical integration. The analytical solutions presented have been verified against numerical solutions from a finite‐element‐based approach and an existing closed‐form solution for double‐layered media with an excellent correlation being found in both cases. A practical application pertaining to advective transport induced by consolidation of underlying sediment layers on contaminant movement within a capped contaminated sediment system is presented. Comparison of the calculated concentrations and fluxes with alternative approaches clearly illustrates the need to consider advection processes. Consideration of the different features of contaminant transport due to varying pore‐water velocity fields in primary consolidation and secondary consolidation stages is achieved via the use of non‐uniform initial concentration distributions within the proposed analytical solutions. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

青海省祁漫塔格地区1∶5万水系沉积物测量衬值异常圈定实例     

赵娟 《地质与勘探》2016,52(3):518-523

青海省祁漫塔格地区位于柴达木盆地西南缘,是青海省重要的铁多金属成矿基地之一。利用88442个野外采样点1∶5万水系沉积物测量数据,采用Geo Expl软件圈定了该地区的衬值异常。衬值是指各元素0.5 km×0.5 km网格化数据与其园域搜索半径5km、移动步长0.5km移动平均值的比值。选用自定义累频"90、95、98、100"确定了异常的外、中、内带。通过常规方法和衬值圈定的异常的对比,表明衬值异常能够削弱不同地质背景差异,使异常形态更为规整,浓集中心更为明显,并且可能发现新异常。  相似文献   

The use of WorldView-2 satellite imagery to model urban drainage system with low impact development (LID) Techniques     

Moh Moh Lin Khin  Ahmed Shaker  Darko Joksimovic 《国际地球制图》2016,31(1):92-108

Within a wide range of best management practices for stormwater management in urban areas, there has been an increasing interest in source control measures. Source controls such as low-impact development (LID) techniques are potentially attractive as retrofit options for older developed areas that lack available land to implement conventional measures such as stormwater management ponds. Hence, distributed urban drainage models requiring detailed representation of developed drainage areas should be developed to accurately estimate the benefits that LIDs may provide. This study (1) presents a two-stage classification process on a high-resolution WorldView-2 image, and (2) demonstrates how to use the extracted land cover information in the subsequent hydrologic modelling and assessment of different LIDs’ performance. The proposed two-stage classification method achieved an overall accuracy of 80.6%, whereas a traditional pixel-based achieved 68.4% in classifying the same urban area into six land cover classes. From the classification results, the hydrologic properties of micro-subcatchments were imported in the United States Environmental Protection Agency Storm Water Management Model to assess the performance of LIDs. A reduction of run-off volume 18.2% and 37.1% was found with the implementation of porous pavement and bioretention, respectively, in a typical low-rise residential area located in the city of San Clemente, California, US. The study demonstrates the use of high-resolution remote sensing image to aid in evaluating LID retrofit options, and thus benefits in situations where detailed drainage area information is not available.  相似文献   

降水井改造为原位生产井的工艺设计及应用     

吕士东  孙友宏  李强  郭威  周科  王思远 《世界地质》2016,35(4):1185-1194

为有效地扩大油页岩原位开采区域和节约油页岩原位开采的成本,需将废置的降水井改造成为原位生产井。根据降水井与原位生产井井身结构的相似性,对农安油页岩原位开采先导试验工程基地的降水井改造工艺进行了设计和优化。同时研发了偏心轮式套管割管装置及三爪式套管打捞装置用于拔管施工。工程实践证明,该工艺具有步骤简单、合理、高效以及价格低廉等特点。偏心轮式套管割管装置及三爪式套管打捞装置应用在降水井改造中,均取得理想的效果。  相似文献   

钻孔压水试验水压式栓塞排水泄压问题研究          下载免费PDF全文

裴熊伟 《探矿工程》2016,43(3):56-59

压水试验水压式栓塞较其他类型栓塞可靠、灵活,但一直存在试验结束后排水泄压难题,使该类型栓塞使用局限于浅孔及地下水位高的钻孔。本文对该问题进行了研究,提出了解决方案,设计了新型水压式栓塞结构。解决了一直以来水压式栓塞的排水泄压难题,突破了试验孔深限制,使水压式栓塞能得到广泛应用。介绍了该新型水压式栓塞的结构和工作原理以及工程应用效果。  相似文献   

辐射井技术在尾矿库降排水工程中的应用          下载免费PDF全文

阮茂盛  奚兴富  周晨晨 《探矿工程》2016,43(4):72-75

尾矿库是我国重大危险源之一,而尾矿库内的浸润线又是坝体安全的重要指标之一,为有效排出尾矿中的水,降低尾矿库内浸润线,本文通过辐射井技术在尾矿库降排水工程中应用的多个成功工程实例,归纳、总结并提出该技术在尾矿库应用过程中的设计思路、施工要点及工艺方法等。  相似文献   

高速公路通道下沉开裂治理实践     

张锦灵  豆敬峰  李金刚 《探矿工程》2018,45(6):75-80

河南省省道323线登封市大冶镇一段公路软弱地基以及路面出现不均匀沉降,通道箱涵开裂,边坡为欠稳定边坡。将事故路段分为4个区域进行加固治理。通过采用注浆加固路基基础、设置坡面排水系统、提高地基的承载能力等治理措施,保证了道路的通行能力。  相似文献   

Fluorine and chlorine in apatites,micas, and amphiboles of layered trap intrusions of the Siberian Platform     

V.V. Ryabov  O.N. Simonov  S.G. Snisar 《Russian Geology and Geophysics》2018,59(4):363-373

Geochemistry of chlorine and fluorine in apatites, micas, and amphiboles in rocks from eight intrusive complexes of the Siberian Platform has been first studied on the basis of new factual and analytical data (more than 1000 analyses). The main attention is focused on minerals from layered intrusions. Most apatites show F > Cl; the maximum contents of halogens are specific to chlorapatite (6.97 wt.% Cl) and fluorapatite (6.04 wt.% F). The total f value (f = Fe/(Fe + Mg), at.%) of femic minerals varies from 2 to 98 at.% in micas and from 22 to 95 at.% in amphiboles. The Cl-f and F-f trends show an increase in the Cl content and a decrease in the F content in the minerals with increasing f. Chlorine clearly exhibits ferrophilic properties, and fluorine has magnesiophilic properties. The halogen-richest minerals are fluorophlogopite (F = 7.06 wt.%, f = 7 at.%), chlorannite (Cl = 6.30 wt.%, f = 89 at.%), and chloroferrihastingsite (Cl = 5.22 wt.%, f = 90 at.%). Coexisting micas and amphiboles in the rocks are close in f value, but the micas are richer in Cl than the amphiboles. We assume that the halogen-containing minerals crystallized at the high pressure of halogen-hydrocarbon fluids at the levels of the MW, IW, and QIF buffers. The reducing conditions of the magmatism process are also evidenced by the presence of graphite and native metals in the rocks. The similarity of the Cl-f and F-f trends of micas and amphiboles from different intrusive complexes indicates the same mechanisms of the melt differentiation and mineral crystallization.  相似文献