首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 78 毫秒
1.
成槽施工是地下连续墙施工的重要工序,厦门地铁3号线湖滨东路站地下连续墙施工中采用YCJF20型冲击反循环钻机冲击钻进法进行成槽施工。介绍了YCJF20型钻机的主要技术参数、特点和工作原理,以及导墙和导孔施工、钻机布置、泥浆制备、冲钻成槽等成槽施工过程。  相似文献   

2.
地下连续墙是一种科学先进的施工方法。由于地下连续墙既可用作地下工程的防渗挡土结构墙,又可用作建筑物的承重基础墙,所以已成为地下工程的一种基本的选择方案。根据8个地下连续墙工程项目的施工经验,叙述地下连续墙的导墙、成槽、钢筋混凝土灌注、泥浆处理等施工工艺,并列举了3个工程实例。  相似文献   

3.
地下连续墙施工力学机理三维数值分析   总被引:4,自引:0,他引:4  
采用三维有限差分方法,模拟了地下连续墙成槽开挖及混凝土浇筑施工全过程,研究了连续墙槽段外围土层在地下连续墙施工过程中的应力状态与变形形态,并将计算结果和现场实测结果进行比较。结果表明,数值计算应力结果与实测结果规律基本一致,但槽段底部数值计算应力变化梯度比实测值略大,采用该计算方法模拟地下连续墙施工全过程具有一定的可行性和较强的可靠性。  相似文献   

4.
王志强  王建庄 《探矿工程》2001,(1):66-66,63
介绍了CJF-12型钻机反循环钻机在黄河堤岩荷泽段施工地下超薄连续墙的概况。根据工程实际情况,对钻机进行了改造,并设计了专用钻具,取得了较好效果。  相似文献   

5.
含砂性土等软土地层地下连续墙成槽施工,基槽侧壁易扰动坍塌,影响地下连续墙施工质量。降低泥浆失水量、适当提高泥浆粘度和防塌是护壁成槽的关键。结合宁波轨道交通车站基坑地下连续墙成槽施工,采用部分水解聚丙烯酰胺(PHP)、聚丙烯腈钙(CPAN)和硝基腐植酸钾(NKHm)作为添加剂,根据正交试验测定泥浆性能优化配比。研究表明:PHP失水量小,泥皮薄;CPAN和NKHm对降失水量效果明显,粘度适中。将试验结果应用于工程实践,护壁效果好。  相似文献   

6.
简要介绍了CJF-20型冲击反循环钻机的特点、技术参数,以及应用冲击循环钻机施工三峡二期堰地下连续墙、部分大口径钻孔灌注桩工程实例。  相似文献   

7.
概述了大直径空心桩施工技术的发展现状,在调研分析的基础上,借鉴地下连续墙施工技术,提出了一种新型的环形孔钻具,并对其结构、工作原理、应用条件及施工步骤等进行了阐述。  相似文献   

8.
插管悬挂式气举反循环钻具是一种新型结构的气举反循环钻具。它不同于双壁式气举反循环钻具,而是通过插入一根独立的插管建立压缩空气通道,具有结构简单、使用方便、耐用性好、通用性强的特点。以工程实例为基础,对插管悬挂式气举反循环钻具在地热井施工中的钻具配置、专用工具及应用注意事项进行了说明,针对在地热井施工中出现的问题及改进方法进行了详细研究。  相似文献   

9.
为了分析地下连续墙成槽施工过程中对槽壁周边土体变形的影响程度,在南京河西地区某基坑工程的地下连续墙正式施工前进行了墙厚1.2 m、宽度4.5 m、深度61.0 m的成槽试验。结果表明,当成槽机向下开挖时,土体在不同深度处出现不同程度的向坑外的位移现象,部分监测数据显示为负值。在成槽施工完成后,水平位移变化出现缓慢回弹的趋势,并在成槽后的两天时间内变化速率渐渐变小。单幅地下连续墙成槽过程中槽壁周边土体的变形对环境影响不大。  相似文献   

10.
目前,我国使用的地下连续墙稳定液品种单一、性能较差,不能满足复杂地怪的地下连续墙施工。根据现代地下连续墙成槽工艺及地下连续墙对稳定液的要求,我们在室内研制了聚合物溶液,以满足现代地下施工的需要。  相似文献   

11.
Pant-y-ffynnon Quarry in South Wales yielded a rich cache of fossils in the early 1950s, including articulated specimens of new species (the small sauropodomorph dinosaur Pantydraco caducus and the crocodylomorph Terrestrisuchus gracilis), but no substantial study of the wider fauna of the Pant-y-ffynnon fissure systems has been published. Here, our overview of existing specimens, a few described but mostly undescribed, as well as freshly processed material, provides a comprehensive picture of the Pant-y-ffynnon palaeo-island of the Late Triassic. This was an island with a relatively impoverished fauna dominated by small clevosaurs (rhynchocephalians), including a new species, Clevosaurus cambrica, described here from a partially articulated specimen and isolated bones. The new species has a dental morphology that is intermediate between the Late Triassic Clevosaurus hudsoni, from Cromhall Quarry to the east, and the younger C. convallis from Pant Quarry to the west, suggesting adaptive radiation of clevosaurs in the palaeo-archipelago. The larger reptiles on the palaeo-island do not exceed 1.5?m in length, including a small carnivorous crocodylomorph, Terrestrisuchus, and a possible example of insular dwarfism in the basal dinosaur Pantydraco.  相似文献   

12.
Lithostratigraphy, physicochemical stratigraphy, biostratigraphy, and geochronology of the 77–70 Ma old series bracketing the Campanian–Maastrichtian boundary have been investigated by 70 experts. For the first time, direct relationships between macro- and microfossils have been established, as well as direct and indirect relationships between chemo-physical and biostratigraphical tools. A combination of criteria for selecting the boundary level, duration estimates, uncertainties on durations and on the location of biohorizons have been considered; new chronostratigraphic units are proposed. The geological site at Tercis is accepted by the Commission on Stratigraphy as the international reference for the stratigraphy of the studied interval. To cite this article: G.S. Odin, C. R. Geoscience 334 (2002) 409–414.  相似文献   

13.
Robert L. Linnen   《Lithos》2005,80(1-4):267-280
The solubilities of columbite, tantalite, wolframite, rutile, zircon and hafnon were determined as a function of the water contents in peralkaline and subaluminous granite melts. All experiments were conducted at 1035 °C and 2 kbar and the water contents of the melts ranged from nominally dry to approximately 6 wt.% H2O. Accessory phase solubilities are not affected by the water content of the peralkaline melt. By contrast, solubilities are affected by the water content of the subaluminous melt, where the solubilities of all the accessory phases examined increase with the water content of the melt, up to 2 wt.% H2O. At higher water contents, solubilities are nearly constant. It can be concluded that water is not an important control of accessory phase solubility, although the water content will affect diffusivities of components in the melt, thus whether or not accessory phases will be present as restite material. The solubility behaviour in the subaluminous and peralkaline melts supports previous spectroscopic studies, which have observed differences in the coordination of high field strength elements in dry vs. wet subaluminous granitic glasses, but not for peralkaline granitic glasses. Lastly, the fact that wolframite solubility increases with increasing water content in the subaluminous melt suggests that tungsten dissolved as a hexavalent species.  相似文献   

14.
Calcite samples were extracted both from the rock matrix and the superficial coating of a karstified fault plane of an underground quarry, located in the eastern border of the Paris basin. The karstification is dated as Quaternary. Analysis of mechanical calcite twinning reveals that only the calcite matrix has also undergone a compression trending WNW that can be attributed to the Mio-Pliocene alpine collision. Both coating and matrix have undergone a strike-slip regime with σ1 roughly trending north–south, that could correspond to the regional present-day state of stress, a strike-slip compression rather trending NNW, modified by local phenomena. To cite this article: M. Rocher et al., C. R. Geoscience 335 (2003).  相似文献   

15.
HYDROGEOLOGY     
正20141756 Chen Ruige(Mathematical College,China University of Geosciences,Beijing100083,China);Zhou Xun Numerical Simulation of Groundwater Level Fluctuation in a Coastal Confined Aquifer with Sloping Initial Groundwater Level Induced by the Tide(Geological Bulletin of China,ISSN1671-2552,CN11-4648/P,32(7),2013,p.1099-1104,6 illus.,16 refs.) Key words:confined water,groundwater level  相似文献   

16.
正20141408 Cai Jia(Institute of Geology,Chinese Academy of Geological Sciences,Beijing100037,China);Liu Fulai Petrogenesis and Metamorphic P-T Conditions of Garnet-Spinel-Biotitebearing Paragneiss in Danangou Area,Daqingshan-Wulashan Metamorphic Complex Belt(Acta Petrologica Sinica,ISSN1000-0569,CN11-1922/P,29(7),  相似文献   

17.
18.
正20142386An Guoying(China Aero Geophysical Survey and Remote Sensing Center for Land and Resources,Beijing 100083,China)Application of Satellite Remote Sensing in Regional Hydrogeological Investigation:Taking Cenozoic Strata in Wenquan Sheet(1∶250 000)of Karakoram Range as an Example(Geosci-  相似文献   

19.
正20141016An Chengbang(Key Laboratory of Western China’s Environmental Systems,Ministry of Education,Lanzhou University,Lanzhou 730000,China);Zhao Yongtao Lake Records during the Last Glacial Maximum from Xinjiang,NW China and Their Climatic Impli-  相似文献   

20.
正20141538 Cao Qing(School of Earth Sciences and Engineering,Xi’an Petroleum University,Xi’an 710065,China);Zhao Jingzhou Characteristics and Significance of Fluid Inclusions from Majiagou Formation,Yichuan Huangling Area,Ordos Basin(Advances in Earth Science,ISSN1001-8166,CN62-1091/P,28(7),2013,p.819-828,7 illus.,3 tables,43 refs.)  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号