百色膨胀土用作路堤填料的试验验证     

湛文涛  赵文建  倪啸  杨和平 《岩土力学》2009,30(Z2):239-243

基于膨胀土可以直接用作路堤填料的分类指标体系,在室内开展了3种不同膨胀土的物理性质、击实性状、强度特性试验研究,验证广西百隆高速公路膨胀土路段的膨胀土也可以直接用作路堤填料,并结合现场实体工程的效果验证用改进CBR值、改进CBR膨胀量和稠度3指标作为膨胀土路堤填料的分类指标体系的合理性。通过对标准CBR试验和改进CBR试验的对比,进一步验证了用改进CBR试验法评定膨胀土承载强度的合理性。由百色膨胀土的不浸水CBR试验,说明可以用封闭包盖对百隆路膨胀土路堤进行物理处治。实体工程中采用土性最差的1号膨胀土做填芯和用红黏土包边,得到的工程效果令人满意。由室内外试验结果,可以得出这3种百色膨胀土都可以直接用作路堤填料。  相似文献   

黄河阶地上某电厂高边坡参数选取及其工程治理     

鄢治华  刘志伟  刘厚健 《岩土力学》2009,30(Z2):465-468

某电厂边坡位于黄河II、IV级阶地之间,最大高度达55 m,主要由上更新统黄土、粉土、砂砾石层及下更新统砂砾卵石层组成。厂址地震基本烈度为Ⅷ度;黄土具有湿陷性;电厂施工及冷却塔等建筑物运行后会对土体的含水率有一定的增加。针对边坡的工程特征,在勘察中获取了多种含水状态下的土体力学参数,在多种工况条件下对边坡进行治理设计。分析认为,在掌握边坡特征和变形破坏模式基础上,选取合理的参数、合适的工况,对边坡进行治理设计时才能符合工程实际,做到安全合理、经济适用  相似文献   

深厚吹填粉细砂地基加固试验研究   总被引：1，自引：0，他引：1  

陈越峰  周健  张庆贺  袁夏炜 《岩土力学》2009,30(5):1387-1392

结合上海某深水港集装箱堆场地基加固工程,基于深厚吹填粉细砂的工程特性,通过对无填料振冲挤密法加固的有效性和工艺参数进行现场试验研究,对加固前后的土体变形、超静孔压变化、工艺参数和加固效果等进行了分析和讨论。结果表明,采用无填料振冲挤密法可以加固深层土体、增加粉细砂的密实度,有效消除不均匀沉降和液化危害,效果显著,并拓宽了振冲法的应用范围,可为在类似地基处理中的推广提供参考依据和成功经验。  相似文献   

多排埋入式抗滑桩在武隆县政府滑坡中的应用   总被引：3，自引：0，他引：3  

赵尚毅  郑颖人  李安洪  邱文平  唐晓松  徐俊 《岩土力学》2009,30(Z1):160-164

武隆县政府滑坡规模巨大,滑坡体长280～340 m,滑坡体厚15～35 m,滑坡推力最大达9 000 kN/m,采用一排抗滑桩难以抵挡如此巨大的滑坡推力。设计采用了多排埋入式抗滑桩进行支挡,将桩的长度减小了约1/3,节省了工程投资。介绍了该滑坡采用埋入式抗滑桩的设计计算方法,重点介绍了采用有限元强度折减法对多排桩的推力及桩的长度设计与计算,供同行或类似工程参考。  相似文献   

高能级强夯处理湿陷性黄土设计施工检测应注意的问题   总被引：1，自引：0，他引：1  

詹金林  水伟厚 《岩土力学》2009,30(Z2):457-460

对3 000～15 000 kN.m高能级强夯加固湿陷性黄土的工艺进行了详细地探讨,讨论了设计、施工、检测各个环节可能存在及所需要注意问题,供类似工程优化设计和现场指导施工、检测借鉴。  相似文献   

A sediment record of trace metal loadings in the Upper Mississippi River     

Steven J. Balogh  Daniel R. Engstrom  James E. Almendinger  Charlene McDermott  Jie Hu  Yabing H. Nollet  Michael L. Meyer  D. Kent Johnson 《Journal of Paleolimnology》2009,41(4):623-639

Sediment cores from Lake Pepin, a natural lake on the Upper Mississippi River, reveal the historical trends in trace metal use and discharge in the watershed. Lead-210 dated concentration profiles of trace metals (Ag, Cd, Cr, Cu, Hg, Pb, V, Zn) in sediment cores from throughout the lake generally showed low and stable concentrations prior to settlement (circa 1830), peak concentrations between 1940 and 1975, and substantial decreases thereafter. Whole-lake sediment accumulation rates increased greatly over the period of record, from 79,000 metric tons year⁻¹ prior to 1830, to 876,000 metric tons year⁻¹ during the 1990s. Whole-lake accumulation rates of most trace metals peaked in the 1960s but decreased sharply after that. Sediment and trace metal accumulation rates decreased in the downstream direction, and approximately two-thirds of the sediment and trace metal mass accumulated in Lake Pepin since 1800 was deposited in the upper 30% (by area) of the lake. The dramatic declines in trace metal concentrations and accumulation rates in Lake Pepin sediments since 1970 coincide with increased pollution control and prevention efforts throughout the watershed, including the implementation of secondary treatment at a large municipal wastewater treatment plant upstream. This is one of eight papers dedicated to the “Recent Environmental History of the Upper Mississippi River” published in this special issue of the Journal of Paleolimnology. D.R. Engstrom served as guest editor of the special issue.  相似文献   

西平公路内社段滑坡稳定性分析与对策研究     

卓万生 《地质灾害与环境保护》2006,17(4):28-32

论述了西平公路内社段东南侧后山高边坡的地形地貌、滑坡发育特征、地质特征和成因机制分析,采用华宁岩土工程勘察软件统计,判定该滑体的稳定性,再通过传递系数法进行稳定性验算,并针对边坡的主要特征和工程实际情况,对该隐患地段的治理方案进行综合比选,提出了较为科学可行、经济合理的防治措施。  相似文献   

Stability analysis and treatment of No.2 dump of Nanfen iron mine     

Yan XU  Lei NIE  Huangping DING  Yin WANG  Jian LIU  Wei LU  Zhenying ZHANG  Xue GONG  Shiwei SHEN 《世界地质(英文版)》2006,9(2)

On the basis of the study on the engineering geological characteristics of No.2 dump of Nanfen iron mine and the analysis of the failure mode of dump landslide, the stability of the present dump, the stability of the dump 20 years later and the stability of double-bench dump are analyzed. Then, the debris flow risk is evaluated by fuzzy mathematics method. Finally, the comprehensive treatment for the dump is suggested. It is concluded that ① In rainy and snowmelt period, the stability would be decreasing sharply when ground water is not drained out in time; ② Double-bench dumping mode will improve stability of the dump little; ③ Debris flow risk is middle danger. The interim debris flow with medium scale may occur. ④ Monitoring, draining and baffling work ought to be well done. ⑤ In order to prevent the damage of landslide and debris flow, three measures are adopted, including setting rockfall net, setting the debris flow barrier and removing the residents.  相似文献   

Pathogenic agents in freshwater resources     

Edwin E. Geldreich 《水文研究》1996,10(2):315-333

Numerous pathogenic agents have been found in freshwaters used as sources for water supplies, recreational bathing and irrigation. These agents include bacterial pathogens, enteric viruses, several protozoans and parasitic worms more common to tropical waters. Although infected humans are a major source of pathogens, farm animals (cattle, sheep, pigs), animal pets (dogs, cats) and wildlife serve as significant reservoirs and should not be ignored. The range of infected individuals within a given warm-blooded animal group (humans included) may range from 1 to 25%. Survival times for pathogens in the water environment may range from a few days to as much as a year (Ascaris, Taenia eggs), with infective dose levels varying from one viable cell for several primary pathogenic agents to many thousands of cells for a given opportunistic pathogen. As pathogen detection in water is complex and not readily incorporated into routine monitoring, a surrogate is necessary. In general, indicators of faecal contamination provide a positive correlation with intestinal pathogen occurrences only when appropriate sample volumes are examined by sensitive methodology. Pathways by which pathogens reach susceptible water users include ingestion of contaminated water, body contact with polluted recreational waters and consumption of salad crops irrigated by polluted freshwaters. Major contributors to the spread of various water-borne pathogens are sewage, polluted surface waters and stormwater runoff. All of these contributions are intensified during periods of major floods. Several water-borne case histories are cited as examples of breakdowns in public health protection related to water supply, recreational waters and the consumption of contaminated salad crops. In the long term, water resource management must focus on pollution prevention from point sources of waste discharges and the spread of pathogens in watershed stormwater runoff.  相似文献   

EU shipping in the dawn of managing the ballast water issue   总被引：2，自引：0，他引：2  

David M  Gollasch S 《Marine pollution bulletin》2008,56(12):1966-1972

After almost two decades of intensified research, regulatory and political activities focussed on the prevention of harmful organisms and pathogen transfers around the world in 2004 the International Convention on the Management of Ships’ Ballast Water and Sediments (BWM Convention) was adopted to provide a common and globally uniform ballast water management (BWM) approach. Nevertheless, regionally different BWM approaches are developing. By now, many countries around the world seem to be aware of the ballast water issue and its management limitations. In the EU, different approaches have been identified at regional and national scales. The first voluntary BWM requirements at the regional level have been introduced by the HELCOM and OSPAR countries, Adriatic countries have prepared a common approach considering a new legal framework for implementation, and some national level requirements have also been identified. However, a common EU wide BWM approach has not yet clearly emerged. In this paper the authors review the BWM approaches developing in Europe, and describe the EU response on BWM. The authors further provide recommendations which may be considered when developing BWM measures in the EU. This contribution focuses on the BWM issue in European seas in light of the EU Maritime Policy and EU Marine Strategy. The Caspian Sea was also considered.  相似文献