MapGIS区文件自动分类填色的快速实现     

唐桂彬 《测绘与空间地理信息》2015,(1):94-97

针对MapGIS软件在拓扑造区中随机填色而导致图件符号化操作烦琐且极易出错的问题,本文在深入分析MapGIS区明码文件逻辑结构的基础上,运用Excel强大的数据编辑处理功能,提出了快速给区块分类填色的简易方法,并结合土地利用现状图数据进行了实验。结果表明,该方法操作简单,易实现,能够快速地解决一些常见的实际问题。  相似文献   

Experimental study of the seismic behavior of partially concrete‐filled steel bridge piers under bidirectional dynamic loading     

Huihui Yuan  Ji Dang  Tetsuhiko Aoki 《地震工程与结构动力学》2013,42(15):2197-2216

The seismic behavior of steel bridge piers partially filled with concrete under actual earthquake conditions was investigated by using 20 square section specimens subjected to static cyclic loading tests and single‐directional and bidirectional hybrid loading tests. Acceleration records of two horizontal NS and EW directional components for hard (GT1), medium (GT2), and soft grounds (GT3), obtained during the 1995 Kobe earthquake, were adopted in dynamic tests. Experimental results clearly showed that maximum and residual displacements under actual earthquake conditions cannot be accurately estimated by conventional single‐directional loading tests, especially for GT2 and GT3. A modified admissible displacement was proposed on the basis of bidirectional loading test results. The concrete fill can effectively improve the seismic resistance performance if the concrete inside the steel bridge piers is sufficiently high in quantity. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

对某钢厂建设中边坡支护问题的研究          下载免费PDF全文

宗士昌 《探矿工程》2014,41(8):76-80

利用修整斜山坡场地的边坡支护的实践经验,研究了扶壁式＋预应力锚杆挡墙、板式锚杆挡墙、格构式锚杆挡墙和岩石锚喷支护方式在边坡支护中的应用,可为以后类似工程的设计与施工提供参考依据。  相似文献   

井场边坡稳定性评价及工程处治方案     

林泽俊 《地质灾害与环境保护》2012,23(2):71-76

乐山市境内某井场平整形成填方边坡.边坡坡脚井场污水池开挖中,临空面和边坡支挡工程均出现变形破坏.根据变形破坏的分布规律,从场地地形、建筑物分布、边坡特征和原始坡体物质结构方面,分析该边坡变形机理,评价其稳定性影响因素.并采用极限平衡法对边坡的稳定性及下滑推力进行计算.在此基础上,针对性地提出该边坡的工程处治方案,保证后期井场及污水池的作业安全.  相似文献   

曹妃甸地区基坑支护降水方案选择及设计建议          下载免费PDF全文

刘来新 《探矿工程》2012,39(4):44-47

首钢京唐钢铁联合有限责任公司是一个在曹妃甸岛上吹填砂造地形成的场地上新建的大型现代化精品钢铁基地。分析了该建筑场地的地质环境情况和常用的基坑支护、降水方法,对该建筑场地上的建（构）筑物的基坑支护、降水设计及方案选择提出建议。  相似文献   

新型快速锚固锚索的研发及应用          下载免费PDF全文

和曙泉  徐国民 《探矿工程》2012,39(7):71-76

介绍了直立高填方区边坡治理工程中应用的一种新型的快速锚固技术———预应力混凝土管水平向快速锚固锚索的研发过程,阐述了其力学原理及其构造、特性,并结合工程实例,介绍了新型快速锚固锚索的实施过程及技术要点。  相似文献   

化学方法改良吹填土固结沉降性质研究   总被引：1，自引：1，他引：0  

侯鑫  马巍  李国玉  S.K.Nikolaeva  王清 《冰川冻土》2016,38(4):996-1002

大连市大窑湾港区的吹填土为高分散性低液限粉质黏土,其特点是亲水性高,含水量大,排水率低,这造成了吹填土承载力低,在荷载作用下变形量大,在很长一段时间内无法作为正常建筑地基使用.通过在盐水环境下添加不同剂量的浓度为0.1%的絮凝剂Praestol-2515或Praestol-650溶液,可以观察到土颗粒迅速聚合,土粒粒径明显增大,粒间胶结更加均匀和紧密,形成絮状物,从而促进了土颗粒与自由水分的分离,导致过饱和吹填土（悬浊液）沉降速度大大提高,极大地缩短了吹填土的排水固结时间,在短期内达到建筑地基所需要的变形量和承载能力.研究结果对于沿海地区过饱和吹填土的造陆工程,以及类似的高含水率黏性土的地基处理具有重要的启示意义.  相似文献   

GEOMORPHIC AND STRATIGRAPHIC COMPLEXITY: HOLOCENE ALLUVIAL HISTORY OF UPPER WOLLOMBI BROOK, AUSTRALIA     

WAYNE D. ERSKINE  M.D. MELVILLE 《Geografiska Annaler: Series A, Physical Geography》2008,90(1):19-35

Holocene and post‐European settlement alluvial histories of three nested drainage basins were reconstructed from detailed litho‐ and chronostratigraphy of cut and fill terraces and flood‐plains in the upper Wollombi Brook catchment. Fernances Creek (13.8 km²) valley fill consisted of intercalated thin mud sheets deposited in ephemeral swamps and thick sand sheets deposited by discontinuous channels. Dairy Arm (39.8 km²) valley fill was more complex, with inset alluvial fills in the upper basin and overlapping vertically stacked fills in the lower basin. However, correlative lithostrati‐graphic units were not found on all tributaries. Furthermore, basal radiocarbon dates on the last inset fill of four tributaries did not overlap, allowing for plus or minus twice the standard deviation of the reported ages. Wollombi Brook (341 km²) valley fill was also complex, with longitudinally discontinuous units, most of which were not found in the two tributaries. Upstream late Holocene channel incision was coeval with downstream chain of ponds because sediment generated by incision was stored in the intervening valley. Historical channel incision occurred between 1838 and 1867 on Fernances Creek at a locally steeper section of valley floor during the period of peak population and frequent floods immediately after a road crossing was constructed, but coincided with a catastrophic flood on Dairy Arm (June 1949) and on Wollombi Brook (1927). Lack of correlative litho‐ and chronostrati‐graphic units plus out‐of‐phase post‐European incision indicate that stratigraphic complexity is a function of geomorphic complexity due to the operation of geomorphic thresholds and complex response.  相似文献   

Biogrouting of hydraulic fill fine sands for reclamation projects     

Jijian Lian  Hongyin Xu  Xiaoqing He  Dengfeng Fu  Shuwang Yan 《Marine Georesources & Geotechnology》2013,31(2):212-222

ABSTRACT

Biogrouting, which is a new method for soil improvement, was used in an attempt to cement a type of hydraulic fill fine sands (called black sands) in reclamation projects in Tianjin, China, to form a working layer for mechanical equipment. Several factors influencing biogrouting with regard to cementing solution, including injection frequency, reaction time, concentration, and flow rate, were controlled to prepare black sand columns. This paper reports on an investigation of bacterial fixation, calcium ion utilization, and calcium carbonate distributions of biogrouted sand specimens. At the end of the tests, the geotechnical performances of the sand specimens were determined. The results showed that the biogrouting method effectively solidified black sands, by increasing the unconfined compressive strength of a sand column to 1.91?MPa and reducing the permeability coefficient by three orders of magnitude. A relationship between the unconfined compressive strengths and calcium carbonate contents was put forward, in addition to a relationship between the permeability coefficients and the calcium carbonate contents. According to the experimental results, some reasonable suggestions regarding the application of biogrouting to the consolidation of hydraulic fill fine sands in reclamation projects were proposed.  相似文献   

Mechanism test on inhomogeneity of dredged fill during vacuum preloading consolidation     

Yingguang Fang  Junwen Huang 《Marine Georesources & Geotechnology》2013,31(8):1007-1017

Abstract

First, this article presents a simulation experiment of hydraulic reclamation, and then a vacuum preloading (VP) test using the sedimentary soil obtained by the first experiment. In the VP test, the distribution and variation of different physico-mechanical parameters before and after the treatment were tested. According to the test results, the concept “non-Terzaghi soil” is proposed to explain the inhomogeneity and its mechanism rendered by “seepage separation.” And then a staged VP (SVP) drainage consolidation method has been introduced to improve the inhomogeneity and seepage curtain phenomena around prefabricated vertical drains (PVDs) during the consolidation. The test results demonstrate that the clogging problem around PVDs has been prevented and the consolidation efficiency has been promoted after the SVP test. It has been noticed that the cumulative drainage volume and the settlement displacement of SVP test were 27% and 24%, respectively, greater than that of VP test, and the soil tends to be more homogeneous. Moreover, it has been shown that the inhomogeneity degree of the permeability coefficient, unit weight, void ratio, water content, cohesion, internal friction angle, compression modulus, and the soil surface settlement in slurry after the SVP test were 3.10, 1.02, 1.03, 1.09, 2.30, 1.92, 1.19, and 1.02, whereas that after VP test was 397.27, 1.07, 1.40, 1.40, 4.74, 3.00, 1.76, and 1.22. Finally, the mechanism of SVP method has been discussed.  相似文献