依兰矿区钻探施工泥浆选型的研究     

魏臣 《中国煤田地质》2007,19(2):72-74

依兰矿区第三系上部的砂泥岩段,因泥岩的水敏水化作用及粗砂岩易坍塌等原因造成,区内钻孔孔壁极不稳定,经常发生粘卡钻具事故。为抑制泥岩的水敏水化,阻止泥岩水化和井壁岩石剥落,增强其防塌能力,在选择腐植酸钾做主剂的基础上选择CMC作降失水增粘剂,选择分子量为300万～500万、水解度30%的聚丙烯酰胺(PAM)作絮凝剂,以加速岩屑沉降,控制固相侵入,降低失水。在钻遇半胶结泥岩时,为防止缩径、坍塌,采用在泥浆中加入重晶石粉,把泥浆比重调整到1.15～1.20g/cm~3,利用泥浆液柱压力控制泥岩缩径和孔壁坍塌。通过实验及现场应用,为该区选择的KHM-CMC-PAM高聚物泥浆配方,能有效地防止水敏性易塌地层的粘卡钻事故,具有护壁防塌、提高钻效等技术效果。  相似文献   

GCL与CCL复合衬垫的等效性分析     

何俊  夏彩虹  胡景山 《水文地质工程地质》2007,34(3):102-106,125

土工合成材料粘土衬垫(GCL)与土工膜(GM)形成的复合衬垫在垃圾填埋场中的应用日益广泛。我国规范中允许在特殊情况下用GCL代替压实粘土(CCL)做垃圾填埋场的衬垫,但是对于“特殊情况”没有明确说明。本文采用数值方法对复合衬垫中无机污染物的对流和扩散进行了计算,从衬垫底部污染物通量和累积量两个角度对GCL复合衬垫和CCL复合衬垫阻滞污染物运移的效果进行了比较,分析两种复合衬垫的等效性,并研究了GCL复合衬垫的适用范围。结果表明,当渗滤液水头较高时,GCL复合衬垫体现出其优势。  相似文献   

湛江海湾大桥塔上锚管定位方法介绍     

李毛毛  刘成龙 《四川测绘》2007,30(2):92-96

斜拉桥是一个受力结构复杂、各构件间相互影响较大的超静定结构体,斜拉索锚管的安装定位是其施工的重点与难点之一。本文结合湛江海湾大桥工程实践,介绍一种涉及到大跨度斜拉桥主塔锚管安装定位的原理、放样数据计算的理论、现场安装测量控制和精度等内容的新方法。  相似文献   

Liner design for waste disposal sites   总被引：5，自引：0，他引：5  

A. Bouazza  W. F. Van Impe 《Environmental Geology》1998,35(1):41-54

 Since the beginning of the 1980s waste disposal has become a particularly sensitive issue. This has led to the development of new legislations in the European Community and internationally which resulted in an array of regulations concerning landfill liner design. This paper comments on different "engineered" containment methods with particular reference to landfill liner design. Suggestions based on the review of the different methodologies are given and a case study is presented. Received: 25 February 1997 · Accepted: 16 December 1997  相似文献   

Damage distribution during the 1994 Northridge, California, earthquake relative to generalized categories of surficial geology     

M.D. Trifunac  M.I. Todorovska 《Soil Dynamics and Earthquake Engineering》1998,17(4):239-253

The spatial distributions of severely damaged buildings (red-tagged) and of breaks in the water distribution system following the 1994 Northridge, California, earthquake (M_L = 6·4) are investigated relative to the local characteristics of surficial geology. The pipe breaks are used as an indicator of nonlinear soil response, and the red-tagged buildings as indicator of severe shaking. The surficial geology is described by several generalized categories based on age, textural character and thickness of the near surface layer. Two regions are studied: the San Fernando Valley and Los Angeles-Santa Monica. The analysis shows that there is no simple correlation between damage patterns and surficial geology. Single family wood-frame buildings were damaged less when built on fine silt and clay (0–3 m thick) from the late Holocene.  相似文献   

Experimental and computational validation and verification of the Stokes–Darcy and continuum pipe flow models for karst aquifers with dual porosity structure     

Xiaolong Hu  Xiaoming Wang  Max Gunzburger  Fei Hua  Yanzhao Cao 《水文研究》2012,26(13):2031-2040

In our previous study, we developed the Stokes–Darcy (SD) model was developed for flow in a karst aquifer with a conduit bedded in matrix, and the Beavers–Joseph (BJ) condition was used to describe the matrix–conduit interface. We also studied the mathematical well‐posedness of a coupled continuum pipe flow (CCPF) model as well as convergence rates of its finite element approximation. In this study, to compare the SD model with the CCPF model, we used numerical analyses to validate finite element discretisation methods for the two models. Using computational experiments, simulation codes implementing the finite element discretisations are then verified. Further model validation studies are based on the results of laboratory experiments. Comparing the results of computer simulations and experiments, we concluded that the SD model with the Beavers–Joseph interface condition is a valid model for conduit–matrix systems. On the other hand, the CCPF model with the value of the exchange parameter chosen within the range suggested in the literature perhaps does not result in good agreement with experimental observations. We then examined the sensitivity of the CCPF model with respect to the exchange parameter, concluding that, as has previously been noted, the model is highly sensitive for small values of the exchange parameter. However, for larger values, the model becomes less sensitive and, more important, also produces results that are in better agreement with experimental observations. This suggests that the CCPF model may also produce accurate simulation results, if one chooses larger values of the exchange parameter than those suggested in the literature. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

A complex variable solution for stress and displacement field around a lined circular tunnel at great depth     

Ming‐Bin Wang  Shu‐Cai Li 《国际地质力学数值与分析法杂志》2009,33(7):939-951

By applying the series expansion technique in the complex variable method established by Muskhelishvili, the plane elasticity problem for the stress and displacement field around a lined circular tunnel in conjunction with the consideration of misfit and interaction between the liner and the surrounding geomaterial is dealt with. The tunnel is assumed to be driven in a homogeneous and isotropic geomaterial. The coefficients in the Laurent series expansion of the stress functions are determined. The complex potentials in the liner and the surrounding geomaterial are explicitly derived, respectively. As an example, the case of a lined circular tunnel located in an isotropic initial stress field but subjected to uniform internal pressure is numerically considered. Numerical results indicate that the installation of tunnel liner can reduce the influences of the tunnel excavation on the in situ displacement and stress fields. However, the relative thickness and rigidity of the liner should be in an appropriate range. In addition, the effect of the tunnel excavation upon the displacement field is more significant than that upon the stress field. As far as the stress field in the surrounding geomaterial is concerned, when the ratio between the cover depth of tunnel and the tunnel radius is larger than 5, the results for the stress field in the paper are applicable. When the ratio between the tunnel depth and the tunnel radius is larger than 20, the results are applicable for the displacement field. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

基于Web的地下管网溯源分析算法研究     

董万虎 《地理空间信息》2021,19(4):71-72,77

利用.NetCore的并行运算机制,实现基于Web的高性能地下管网的溯源分析功能。实践证明当某点管网数据监测出现异常时,能够快速分析所有可能流经该点源头管网信息,并在地图上动态展示分析结果,达到快速定位查询管网源头的区域管理目的。  相似文献   

超长管棚施工技术在山岭隧道软弱围岩中的应用          下载免费PDF全文

冯劲  林廷松  周红升 《探矿工程》2010,37(11):73-75

以黄衢南高速公路阳排尖隧道为例,介绍了大于30 m超长管棚施工技术;并根据现场监控量测数据,对左右洞不同管棚施工技术效果进行对比分析;分析结果显示,一次性施作超长管棚在山岭隧道软弱围岩地段有较好的实用性。  相似文献   

苏通大桥二期试桩后压浆的施工及效果检测          下载免费PDF全文

徐家明  李兆琴  方宏 《江苏地质》2010,34(1):79-83

随着高层建筑和大型桥梁的兴建,钻孔灌注桩在工程中已得到了极为广泛的应用。但是,钻孔灌注桩的固有缺陷,例如孔底沉渣、孔壁泥浆、端阻力、侧阻力发挥不同步等,限制了其承载力的发挥并且沉降较大。由此,钻孔灌注桩压力注浆技术应运而生,并被逐渐应用于工程实践中。所以,对桩的后压浆施工工艺、受力机理等技术问题进行研究是非常重要的。在国内外现有的理论研究和工程应用基础上,通过对苏通大桥Ⅱ期的试桩工程施工,详细阐述了桩端后压浆技术的具体应用。同时,利用钻孔取心及CT检测技术分析后压浆的施工效果。  相似文献