移动式三维激光扫描仪在地下管廊测量中的应用   总被引：1，自引：0，他引：1  

檀继猛  张鹏飞  邵士成  刘秀涵 《测绘通报》2019,(12):156-158,162

针对传统地下管廊测量方法中存在的作业效率低、精度差等问题，笔者试验了一种基于移动手持扫描技术的地下管廊测量新方法。本文以济南市福地街旁某地下管廊为例，制定了可行的测量方案，通过GEOSLAM ZEB-REVO移动式三维激光扫描仪获取点云数据，采用Trimble Realworks软件进行数据后处理，并与全站仪测量结果进行对比分析。结果表明，移动式三维激光扫描仪在地下管廊测量中可以明显提高作业效率且满足测量精度要求，具有较好的应用前景。  相似文献   

A coupled model for simulating surface water and groundwater interactions in coastal wetlands     

Li‐Rong Yuan  Pei Xin  Jun Kong  Ling Li  David Lockington 《水文研究》2011,25(23):3533-3546

Coastal wetlands are characterized by strong, dynamic interactions between surface water and groundwater. This paper presents a coupled model that simulates interacting surface water and groundwater flow and solute transport processes in these wetlands. The coupled model is based on two existing (sub) models for surface water and groundwater, respectively: ELCIRC (a three‐dimensional (3‐D) finite‐volume/finite‐difference model for simulating shallow water flow and solute transport in rivers, estuaries and coastal seas) and SUTRA (a 3‐D finite‐element/finite‐difference model for simulating variably saturated, variable‐density fluid flow and solute transport in porous media). Both submodels, using compatible unstructured meshes, are coupled spatially at the common interface between the surface water and groundwater bodies. The surface water level and solute concentrations computed by the ELCIRC model are used to determine the boundary conditions of the SUTRA‐based groundwater model at the interface. In turn, the groundwater model provides water and solute fluxes as inputs for the continuity equations of surface water flow and solute transport to account for the mass exchange across the interface. Additionally, flux from the seepage face was routed instantaneously to the nearest surface water cell according to the local sediment surface slope. With an external coupling approach, these two submodels run in parallel using time steps of different sizes. The time step (Δt_g) for the groundwater model is set to be larger than that (Δt_s) used by the surface water model for computational efficiency: Δt_g = M × Δt_s where M is an integer greater than 1. Data exchange takes place between the two submodels through a common database at synchronized times (e.g. end of each Δt_g). The coupled model was validated against two previously reported experiments on surface water and groundwater interactions in coastal lagoons. The results suggest that the model represents well the interacting surface water and groundwater flow and solute transport processes in the lagoons. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

地下矿产开采对天然气管道工程的安全影响评价   总被引：1，自引：1，他引：0       下载免费PDF全文

万继涛  胡松涛  韩祥银  张新文 《山东国土资源》2008,24(6)

西气东输天然气管道工程途经兖州市，穿越杨庄、杨村、兴隆庄等煤矿矿区，压覆煤层埋深变化较大。该文采用预测法对各煤矿在不同开采条件下分煤层对管道运营安全的危害程度进行了评价分析。通过计算表明，煤矿开采埋深越浅，煤层越厚，对管道危害越严重。兴隆庄煤矿3煤层、杨村煤矿煤16t、煤17开采对管道影响强烈，杨庄煤矿煤16t、煤17开采对管道影响中等，兴隆庄煤矿煤16t、煤17开采对管道运营影响小。  相似文献   

Outburst mechanism of Yindapu Glacial Lake in Tibet     

ZHUANG Shuyu  LI Guangjie  CHEN Guoyu  SHU Youfeng College of Construction Engineering  Jilin University  Changchun  China 《东北亚地学研究》2009,(4):200-203

At present, the mechanism research on glacial lake outburst mainly focuses on the ice quake and ice landslide, etc. To some glacial lakes, the seepage deformation is the dominant factor in outburst process. Taking the Yindapu Glacial Lake in Tibet as an example, using SEEP/W module of FEM software （ GEO-STUDIO）, the authors analyzed seepage stability of terminal moraine ridge dam. The leading role of seepage deformation in some glacial lake outburst mechanism is proposed and proved.  相似文献   

In situ quantification of spatial and temporal variability of hyporheic exchange in static and mobile gravel‐bed rivers     

Donald O. Rosenberry  P. Zion Klos  Andrew Neal 《水文研究》2012,26(4):604-612

Seepage meters modified for use in flowing water were used to directly measure rates of exchange between surface and subsurface water in a gravel‐ and cobble bed river in western Pennsylvania, USA (Allegheny River, Q_mean = 190 m³/s) and a sand‐ and gravel‐bed river in Colorado, USA (South Platte River, Q_mean = 9·7 m³/s). Study reaches at the Allegheny River were located downstream from a dam. The bed was stable with moss, algae, and river grass present in many locations. Median seepage was + 0·28 m/d and seepage was highly variable among measurement locations. Upward and downward seepage greatly exceeded the median seepage rate, ranging from + 2·26 (upward) to ? 3·76 (downward) m/d. At the South Platte River site, substantial local‐scale bed topography as well as mobile bedforms resulted in spatial and temporal variability in seepage greatly in exceedence of the median groundwater discharge rate of 0·24 m/d. Both upward and downward seepage were recorded along every transect across the river with rates ranging from + 2·37 to ? 3·40 m/d. Despite a stable bed, which commonly facilitates clogging by fine‐grained or organic sediments, seepage rates at the Allegheny River were not reduced relative to those at the South Platte River. Seepage rate and direction depended primarily on measurement position relative to local‐ and meso‐scale bed topography at both rivers. Hydraulic gradients were small at nearly all seepage‐measurement locations and commonly were not a good indicator of seepage rate or direction. Therefore, measuring hydraulic gradient and hydraulic conductivity at in‐stream piezometers may be misleading if used to determine seepage flux across the sediment‐water interface. Such a method assumes that flow between the well screen and sediment‐water interface is vertical, which appears to be a poor assumption in coarse‐grained hyporheic settings. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

Morphology of pockmarks along the western continental margin of India: Employing multibeam bathymetry and backscatter data   总被引：1，自引：0，他引：1  

Sumanta Dandapath  Bishwajit Chakraborty  Siddaiah M. Karisiddaiah  Andrew Menezes  Govind Ranade  William Fernandes  Davidas K. Naik  K.N. Prudhvi Raju 《Marine and Petroleum Geology》2010

This study addresses the morphology of pockmarks along the western continental margin of India using multibeam bathymetry and backscatter data. Here, for the first time we have utilized the application of ArcGIS (Geographical Information System) for understanding the morphology of pockmarks from the western continental margin of India. The pockmarks observed in water depths of 145–330 m are circular, elliptical or elongated in plan-view, with an average length and width of 157 (±72) m and 83 (±19) m respectively. The average pockmark relief and perimeter are 1.9 (±0.9) m and 412 (±181) m, respectively. The pockmarks have average areas and volumes of 10 759 m² and 15 315 m³ respectively. Spatial separation that coincides with 210 m isobath divides the pockmarks into two groups with differing distributions and morphologies. These pockmarks originated from seepages of biogenic or thermogenic gas or from pore fluids from deeper sources, migrated vertically along the faults. Besides a possible structural control, the pockmark morphologies are also affected by bottom currents and/or by submarine slumping. The average acoustic backscatter strength from pockmark centre is higher (−35 dB) than the average backscatter of the total area (−40 dB), which suggests their possible linkage to the precipitation of diagenitic minerals from biodegradation of seepage material.  相似文献   

基坑降水中的渗出面     

赵晓峰 《岩土工程技术》2012,26(3):137-140

对基坑降水中渗出面产生的机理、影响渗出面高度的因素、渗出面高度的计算、渗出面对基坑工程的危害及采取的措施等进行了详细的论述。工程实践证明,基坑降水工程中渗出面的研究对解决基坑降水中遇到的相关工程问题提供了理论依据。  相似文献   

基于渗透失稳机理的煤与瓦斯突出过程和控突措施作用机制分析     

谢焰  严平辉 《中国煤炭地质》2012,(2):21-25

基于流固耦合理论,提出煤与瓦斯突出属渗透失稳的观点,把临界失稳梯度作为煤体的抗失稳强度指标。通过对突出过程中瓦斯压力梯度变化规律的分析认为：把瓦斯压力梯度达到临界失稳梯度的降压区的煤体视为一个“失稳分层”,突出是煤体以“失稳分层”的形式向前推进的过程,而每个“分层”的失稳表现为“整体性”失稳：延期突出是煤层瓦斯压力梯度逐渐增加并最终达到临界失稳梯度的结果;突出形成的”口小腹大”的孔洞形状．是突出发生过程中流场形态发生变化所致。并将控突措施的作用机理分为4类：降低煤层瓦斯压力、增大巷道气压背景值、延长降压区宽度和提高煤体临界失稳梯度。  相似文献   

水压致裂应力测量系统柔性分析及其对深孔测量的影响   总被引：2，自引：0，他引：2  

王成虎  宋成科  邢博瑞 《现代地质》2012,26(4):808-816

在中国大陆范围内广泛使用的钻杆式水压致裂测试系统由6个部分组成,分别为压力流体控制系统、高压水泵、动力系统、数据记录系统、跨接式封隔器和钻杆系统。该套测试系统又可以分为两类,一种是针对孔深<100 m的浅孔测试系统,一种是针对孔深>100 m的深孔测试系统。对于钻杆式水压致裂系统,钻杆、连接管线以及钻孔变形对系统柔性影响均极微小,封隔器变形和压裂液压缩性是主要影响因素。当测试深度小于100 m时,测试系统柔性主要受封隔器变形和系统压裂液压缩性控制;而当测试深度大于100 m时,测试系统柔性主要受系统压裂液压缩性控制。对于深孔测试,钻杆式水压致裂测试系统柔性过大,会影响重张压力Pr0的准确确定。为了消除系统柔性对深孔测试的影响,可以通过其他方法来确定实验段岩体抗拉强度Tfh,进而确定最大水平主应力SH,或者通过其他方法来直接估算SH。在未来的研究工作中,开发井下传感器和井下流量计将是从根本上消除测试系统柔性影响的一条可靠途径。  相似文献   

冲洪积平原渗流和管流耦合的辐射井结构     

李绅  董新光  吴彬  杨鹏年 《水科学进展》2012,23(5):680-686

利用新疆阿克苏台兰河流域冲洪积平原区非稳定流抽水试验资料,以辐射井为研究对象,结合辐射管内的水头损失及流态,建立粗颗粒潜水含水层渗流和水平管流耦合的地下水流数值模型。利用数值模型,分析在粗颗粒含水层中辐射管不同根数、不同长度、等效渗透系数、辐射井的井径以及不同含水层的渗透系数、不同降深对辐射井出水量的影响,并且根据各参数的相互关系,提出冲洪积平原辐射井的出水量的经验公式。为优化设计辐射井结构及辐射井布置提供依据,对台兰河地下水库的建设及后期运行管理提供了技术支撑。  相似文献