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1.
Bal Krishna Maheshwari Deepak A. Gunjagi 《Geotechnical and Geological Engineering》2008,26(1):101-107
Geotextile filters are rapidly replacing graded granular filters as the standard of practice in geotechnical design. The objective
of the present study is to predict the behavior of the geotextile filter for the locally (Roorkee—India) available soils using
three different geotextiles (two nonwoven and one woven). Nonwoven geotextiles are commonly used in filtration applications.
This paper evaluates the long-term performance of two needle-punched nonwoven geotextiles and one woven geotextile. Filtration
tests on soil–geotextile filter systems were conducted in the laboratory in order to evaluate the filtration and clogging
behavior. Laboratory test program, include evaluation of performance of two different nonwoven and one woven geotextile filters
in combination with locally available Solani River Sand and Clayey Soil. The paper describes the concept and details of the
Fine Fraction Filtration (F3) test and presents data on three different geotextiles, which were evaluated using three different soil types. It is deduced
that in all filtration applications, the non-woven geotextile would perform better than the woven geotextile. 相似文献
2.
以宁波瑞福特气体储运有限公司20,000m3低温乙烯终端和配套公用工程项目的设计为例,介绍了PDSOFT三维配管软件在石油化工储运中的应用。通过项目对该软件的使用过程进行较深入的描述分析、同时对该软件在石油化工储运设计中应用前景和应注意的问题进行了说明。 相似文献
3.
Combined analysis of electrical resistivity and geotechnical SPT blow counts for the safety assessment of fill dam 总被引：1，自引：0，他引：1
Electrical resistivity survey and the geotechnical SPT blow counts (N value) method were simultaneously analyzed to investigate the stability of a center-core type earth-fill dam against the
seepage phenomenon. The coupling of these heterogeneous field methods provided a chance to understand the status of underground
material by comparing the geophysical and geotechnical view. The analysis shows that the zones with low resistivity value
generally have low N value, which means low stiffness. However, some zones with a high resistivity pattern are not accompanied by an increase
of its N value, and are even showing a lower N value. These results imply that one should be careful to directly correlate resistivity value with the real status of the
core material of a fill dam. And a highly resistive zone may be in poor status due to the effect of increase of resistivity
value as a result of the piping condition. Additional laboratory tests show that there is a deficiency of fine soil particles
believed as the clay at the troubled region, which means an increase in resistivity value. Therefore, multiple explorations
should be planned to reduce the uncertainty in application of geophysical methods to dam safety evaluation in order to compensate
the resistivity information of core material. 相似文献
4.
M. Heshmati J. Shamshuddin N.M. Majid M. Ghaituri 《Journal of Arid Environments》2011,75(11):1072-1082
Part of the mountainous semi-arid areas of Iran is geologically and topographically susceptible to landslides. A study was conducted at the Merek catchment, Iran which is geologically characterized by limestone, sandstone, shale and marls so as to determine the factors responsible for the occurrence of landslides. In this study, geomorphological units within the catchment were mapped by overlapping geological, topographical, land use and erosion data, using satellite image and GIS. Rocks and soils were sampled within each unit to determine their physico-chemical and mineralogical properties. It was found that landslides have affected about 15% of the Merek catchment and that their occurrence were promoted by unstable soils, being eroded at the rate of 18.57 t ha−1 yr−1. These landslides were initiated by crack formation in areas having smectite, a mineral which can swell and contract, depending on the availability of water. Smectite is the dominant mineral in about 80% of the area affected by landslides. Low aggregate stability in the topsoil further promotes the occurrence of landslides. Field verification showed that landslides occur mainly in the forest where the canopy cover is less than 15% with slope of 10-40%. Deforestation, overgrazing and improper tillage practices were found to accelerate landslides in this catchment. 相似文献
5.
Ground cracks in Ethiopian Rift Valley: facts and uncertainties 总被引：2，自引：0，他引：2
No accurate relationship has been obtained in this study between ground cracks in Ethiopian Rift Valley and the most common causes of earth fissures such as aquifer-system compaction and increased horizontal seepage stresses. This is due to the fact that the level of groundwater withdrawal responsible for these processes is still negligible in Ethiopia. If aquifer-system compaction and increased horizontal seepage stresses have a certain role, then it should be through the long-term effect of groundwater flow from basins to neighboring lakes. The ground cracks appeared also not to have a direct link with active faulting or distant earthquakes. Structurally, the Ethiopian Rift Valley is dominated by NE–SW-trending tensional faults, but no evidence is obtained in this study to associate the process of surface cracking with major tectonics. However, an aseismic elastic strain, which originates at depth and propagates upward through sediments without the formation of bedrock faults, could result in conditions conducive to the development of cracks. Then, fissures might ultimately be created after heavy rainfalls by near-surface processes such as piping and hydrocompaction along water-line sources. 相似文献
6.
Sinkhole development along the western shore of the Dead Sea became a major concern in 1990 with the appearance of a series
of holes 2–15 m diameter and up to 7 m deep in the Newe Zohar area. One of these sinkholes, below the asphalt surface of the
main road along the western shore of the Dead Sea, was opened by a passing bus. Repeated infilling and collapse of these holes
indicated the extent of this ongoing process and the significance of this developing hazard. Since then sinkholes have developed
in other areas including Qalia, Ein Samar, Ein Gedi and Mineral Beach.
Three main types of sinkholes have been recognized. Gravel holes occurring in alluvial fans, mud holes occurring in the intervening
bays of clay deposits between fans and a combination of both types at the front of young alluvial fans where they overlap
mud flats. Fossil, relict sinkholes have been observed in the channels of some old alluvial fans.
Sinkhole development is directly related to the regression of the Dead Sea and the corresponding lowering of the regional
water table. Continuation of this process widens the neritic zone enveloping the sea and increases the sinkhole hazard of
the region.
Received: 4 February 1999 · Accepted: 8 April 1999 相似文献
7.
关于物理潜蚀作用及其概念模型的讨论 总被引：2，自引：0，他引：2
在对国内外物理潜蚀作用相关文献进行调研的基础上回顾了潜蚀作用的研究历史,对目前物理潜蚀作用研究中存在的问题进行了总结。指出潜蚀工程地质问题在各类工程建设活动中已经变得越来越突出,但由于潜蚀作用发生环境的多样性、作用方式的复杂性、发生过程的随机性等原因,造成实际应用中将各种潜蚀作用尤其是物理潜蚀作用过程的概念经常混淆。对"管涌"、"渗透压密"、"接触管涌"、"接触冲刷"、"流土"、"突涌"、"接触流土"、"流砂"、"流滑"等物理潜蚀作用的发生机理进行了深入细致的分析,在此基础上对目前一些界定不严格的物理潜蚀相关概念进行了辨析和澄清,初步建立了清晰的物理潜蚀作用概念模型,为潜蚀工程地质进一步研究奠定了基础。 相似文献
8.
高压摆喷注浆在长沙市堤防建设中的应用 总被引：1，自引：0，他引：1
为防止长沙市21.8km重点堤防的管涌、涌漏等隐患，提高堤防的抗洪能力,采用高压摆喷浆施工对其进行了整修、加固。较详细地介绍了设备的选择、孔间距及工艺参数的调整、工序安排和工程质量及检测方法。堤防中摆喷连结心墙的围井检测表明，高喷注浆是处理长沙市防洪堤防第四系松散地基的一项设备简便、噪音小、施工快、成本低、防渗效果好的工艺。 相似文献
9.
A numerical approach for simulating piping erosion is proposed based on an auto-adaptive moving mesh. This approach adapts a flownet mesh (FM) to discretize the domain. It reduces the simulation of two-dimensional transport of moving particles to one-dimensional problem by taking advantages of flow tube concept. Furthermore, it employs a stepwise procedure to decouple the solid-liquid interaction equations for modeling piping erosion. Specifically, the FM is updated and evolved automatically in accordance to simulated erosion since the flownet is refined in high-velocity regions, where the piping erosion progresses. Therefore, the FM is auto-adaptive to the piping erosion paths. 相似文献
10.
1 INTRODUCTION Tunnel erosion or piping is very common in semi-arid areas. It is often associated with gully system development (e.g., Parker, 1965; Heede, 1971; Harvey, 1982; Crouch, 1983; Gutierrez et al., 1997). It may also become a severe soil conserv… 相似文献