裂隙岩体渗流应力耦合机制研究

隧洞开挖前,岩体中的地下水与围岩应力处于一种相对平衡状态,由于隧洞的开挖,一方面使地下水排泄有了新的通道,加速了水循环,破坏了原有的补给一运移一排泄系统的平衡;另一方面,造成围岩应力重分布,部分结构面由于增压而闭合,部分岩体卸荷松弛或产生剪切滑移,人为破坏了原有的地下水渗流条件,使得隧洞自身成为地下水向外排泄的地下廊道...     

晋陕峡谷地区岩溶地下水的同位素及水化学分析

本文研究采用同位素和水化学分析的方法对本地区 2个泉域即天桥和柳林泉域的地下水系统进行分析。研究发现 :(1)天桥泉域北部大部分地区岩溶地下水主要接受了大气降水的补给 ,同时在局部地区也接受了地表水的补给 ;天桥泉域南部岩溶地下水接受了不同高程的大气降水的补给 ,迳流较为活跃。 (2 )柳林泉域岩溶水系统存在浅部和深部 2个子系统 ,来自这 2个系统的地下水互相混合 ,形成了排泄区较为复杂的地下水化学类型     

济枣高铁济泰段对济南泉群的影响及防治对策分析

济枣高铁济泰段通过济南南部的千佛山、慧佛山,其为济南泉群的重要补给区,铁路建设对济南泉群或多或少产生一定影响。文章基于研究区区域地质、水文地质及地下水的补给、径流和排泄、测区地下水动态变化特征等研究,分析评价拟建济枣高铁济泰段对济南泉群的影响,并探讨其防治对策。主要结论有:(1)拟建济枣高铁济泰段主要处于济南单斜地质单元,地层岩性以寒武系-奥陶系的碎屑岩和碳酸盐岩为主,中强富水性;(2)济南泉群主要以其南部的千佛山、慧佛山降水补给为主,其次为河床渗落、孔隙水补给;(3)拟建铁路推荐线位对济南四大泉群的补给、径流影响较小;比选线位对趵突泉和涌泉泉域影响较小,对白泉泉域无影响;(4)工程防治对策首先应遵循铁路轨面标高处于泉群补给区垂直渗流带的地质选线原则,其次隧道设计施工中坚持以堵为主、疏排为辅的综合治理措施。研究成果可为测区类似工程提供借鉴指导。     

宜万铁路马鹿箐隧道地下水示踪试验研究

宜万铁路马鹿箐隧道途经岩溶强烈发育、水文地质条件复杂的灰岩地层,地下暗河管道错综复杂。为了确定马鹿箐隧道区小马滩地下暗河系统与突水溶洞之间的水力联系及暗河系统的补给、径流和排泄条件,采用工业盐(NaCl)作为示踪剂的地下水单元(单一示踪剂)示踪试验方法进行探测。本次试验发现小马滩地下暗河是单一管道流地下暗河,以大气降雨、小马滩上游地表水及地下水为补给源,以蝌蚂口泉群为集中排泄点,龙潭是该暗河系统的天窗。小马滩地下暗河系统地下水流速快,地表水与地下水交替转化迅速,隧道岩溶突水与小马滩伏流的水力联系较弱。     

微承压水条件淤泥质粉质黏土对工程影响浅析

淤泥质土具有高压缩性、高含水量、高灵敏、易扰动、低强度等特性,拟建场区处于白泉泉域的排泄区,受下部承压岩溶水顶托补给,赋存于上部厚层淤泥质粉质黏土中的第四系水具微承压性。下部粉土层为承压含水层,承压水头与潜水水头基本一致,并且在一定程度上接受下部岩溶水越流补给,为中等透水层,若不能较好地处理承压水,基坑突涌风险较大。特殊的水文地质条件,改变了淤泥质粉质黏土的岩土物理力学性质,对基坑的围护结构及基底的加固措施要求较高,影响着施工方案的选择。     

下负荷面剑桥模型在ABAQUS中的开发实现

利用大型有限元软件ABAQUS所提供的UMAT用户材料子程序接口,针对下负荷面剑桥模型开发了子程序,对超固结土的三轴排水与不排水试验进行了数值模拟,将结果与解析解进行了比较;对同样条件下不同OCR超固结土的三轴排水与不排水试验进行了模拟。结果表明:所开发的子程序具有良好的稳定性和较高的计算精度,能够反映超固结土的应力应变特性(如应变软化),得到比较合理的数值分析结果。     

顺平县地下水蓄水构造及找水方向

依据蓄水构造理论,在分析工作区地层、构造条件及地下水补给、径流、排泄条件的基础上,总结出顺平县地下水主要的区域性蓄水构造类型,并提出了该区地下水找水方向与开发利用模式,有助于当地村民合理开发利用地下水。     

豫北平原地下水14C同位素特征

地下水中14C的年代与PMC(与大气中现代碳的百分含量之比)值的大小反映了地下水的补给、迳流、排泄的状况与循环条件。豫北平原地下水中的14C的年代与PMC值反映出:引黄灌区主干渠、山前冲洪积扇、近黄河地带为地下水强补给与迳流带,地下水14C年龄较小,地下水循环交替快;在交接洼地、微咸水区、地下水位下降漏斗区,地下水迳流滞缓,地下水14C年龄较大,地下水循环交替慢。其它资料也验证了此规律。     

广州市水文地质特征分析

综合分析了广州市地下水形成的自然条件、地下水的类型、分布状况、水文地质特征和补给径流排泄条件。为有效管理广州市地下水资源，实施地下水资源的监测与保护提供了详实的依据。     

河南平原第四系地下水氢氧同位素特征与补给分析

河南平原第四系地下水氢氧同位素分布特征,总体上由北向南呈渐高趋势,浅、深层地下水系统水的δ18O值变化规律基本一致。平原北部系统水的δ18O值最低,并随着距离黄河越来越近而变得愈来愈小,呈现出"∨"型变化的特征。平原南部系统水的δ18O值最高,并随着距离淮河越来越近而变得愈来愈大,呈现出"∧"的变化特征。平原中部系统水的δ18O值介于该二者之间,且变化较平缓。浅层系统水主要为大气降水补给。深层系统水受开采作用,使得浅层水的越流补给已成为主要的补给来源。此外,平原北部浅层系统水,黄河侧渗补给亦是沿岸地下水的重要补给来源;而平原南部浅层系统水在接受降水补给的同时,还受到淮河的排泄。     

数学(物理)模拟计算中的降雨补给处理

在地下水和地表水的数学（物理）模拟计算中，降雨补给量的计算是非常重要的内容。本文讨论了有效降雨和无效降雨、降雨的滞后作用、降雨强度及降雨的均匀性对补给的作用，进而给出以月降雨量为单位的补给函数和以日降雨量为单位的补给参数，对水资源评价等涉及到大气降雨补给的计算有重要意义。     

考虑承压含水层间越流的地下水回灌现场试验研究

当场地存在多层层间有一定水力联系的承压含水层时,基坑内降水可引发基坑止水帷幕墙底以下的承压含水层的水头下降,并相应引起坑外多个含水层水位降低,若对所有层进行回灌则将导致成本大幅提高,此时可对某一层回灌,通过越流对其他含水层进行水位补给。通过在天津地铁某车站基坑所在场地开展抽水试验、单井回灌试验、先抽后灌试验对基坑内外的水力联系、不同含水层间的水力联系和隔层回灌的效果进行了研究。结果表明,由于各含水层间之间有一定水力联系导致竖向越流补给较强,基坑内疏干降水可引起坑外承压含水层水头下降并引起坑外地层沉降。对基坑外第Ⅰ微承压含水层进行回灌可有效对其上部潜水层和下部第Ⅱ-1承压层的水头起到抬升作用,通过隔层回灌从而控制其水位下降导致的坑外沉降。对第Ⅰ承压含水层进行回灌对基坑外第Ⅱ-2承压层水位抬升也有一定的作用,但是尚不足以使其因基坑内降水引起的坑外水位下降值完全恢复,建议结合设置此层的备用回灌井以控制其水位下降。     

ESTIMATING RECHARGE FOR BRITISH AQUIFERS

This paper reviews methods of estimating recharge for a wide variety of aquifers in Britain. A soil moisture balance technique is used with direct representation of relevant soil and crop properties. Recharge contributions due to rainfall, runoff from impervious areas and leaking water mains and sewers are considered. In many field situations low permeability strata, which overlie the main aquifer, modify the timing and magnitude of the actual recharge. Runoff from less permeable strata can become runoff-recharge at the aquifer outcrop. Reference is made to several case studies.     

国际铁路工务技术培训包的开发实践与思考

以陕铁职院为例,引入澳大利亚职业培训包理念,以中国铁路技术标准为依据,开发铁路工务技术培训标准包、指南包和资源包,建设模块化、菜单化课程,积极为中国铁路走出国门提供智力支持和人才保障。     

A GIS-based DRASTIC model for assessing aquifer vulnerability in Kakamigahara Heights, Gifu Prefecture, central Japan

Vulnerability assessment to delineate areas that are more susceptible to contamination from anthropogenic sources has become an important element for sensible resource management and land use planning. This contribution aims at estimating aquifer vulnerability by applying the DRASTIC model as well as utilizing sensitivity analyses to evaluate the relative importance of the model parameters for aquifer vulnerability in Kakamigahara Heights, Gifu Prefecture central Japan. An additional objective is to demonstrate the combined use of the DRASTIC and geographical information system (GIS) as an effective method for groundwater pollution risk assessment. The DRASTIC model uses seven environmental parameters (Depth to water, net Recharge, Aquifer media, Soil media, Topography, Impact of vadose zone, and hydraulic Conductivity) to characterize the hydrogeological setting and evaluate aquifer vulnerability. The western part of the Kakamigahara aquifer was dominated by "High" vulnerability classes while the eastern part was characterized by "Moderate" vulnerability classes. The elevated north-eastern part of the study area displayed "Low" aquifer vulnerability. The integrated vulnerability map shows the high risk imposed on the eastern part of the Kakamigahara aquifer due to the high pollution potential of intensive vegetable cultivation. The more vulnerable western part of the aquifer is, however, under a lower contamination risk. In Kakamigahara Heights, land use seems to be a better predictor of groundwater contamination by nitrate. Net recharge parameter inflicted the largest impact on the intrinsic vulnerability of the aquifer followed by soil media, topography, vadose zone media, and hydraulic conductivity. Sensitivity analyses indicated that the removal of net recharge, soil media and topography causes large variation in vulnerability index. Moreover, net recharge and hydraulic conductivity were found to be more effective in assessing aquifer vulnerability than assumed by the DRASTIC model. The GIS technique has provided efficient environment for analyses and high capabilities of handling large spatial data.     

Estimating recharge rates for qanat-based water supply in northern Cyprus: a case study using remotely sensed and in-situ data

The qanat water supply technology, by which gravity drains mountain aquifers into valleys, is considered as a culturally appropriate and ecological sustainable design to meet freshwater development needs in northern Cyprus. This work provides a first-order analysis of the surface water budget to estimate qanat feasibility. The proposed qanat recharge area of 370 km² is in the upper elevations of the limestone dominated Five Finger Mountain Range, is analysed using technical data reports, field visits, and satellite elevation data. Satellite based tropical rainfall measuring mission (TRMM) monthly rainfall totals at a 0.25° grid were tested for complementing sparse precipitation gauge data, but TRMM underestimated gauge observations by 43% in narrow zones of high rainfall during the wet winter months. A water budget for qanat supply used 30-year average gauge records within the qanat recharge region, which set annual precipitation at 529 mm year^?1. A calibrated complementary relationship areal evapotranspiration model established atmospheric outputs at 222 mm year^?1, slightly below the island-average of 280 mm year^?1 estimated by the Cyprus Water Department. Recharge to the qanat aquifer was determined by subtracting evaporation from precipitation, and then allocating 50% of the remainder to environmental services. In the proposed qanat recharge region, this water budget yields an estimated recharge volume of 57 mm³ year^?1. At less than 25% development, this volume satisfies the 13 mm³ annual deficit in northern Cyprus and protects against saltwater intrusion. Additional freshwater conservation measures in northern Cyprus are needed to ensure ecological sustainability in northern Cyprus.     

Grundwasserströmung und -beschaffenheit im Einzugsgebiet der Eckernförder Bucht, Schleswig-Holstein

Within the scope of the Sub-GATE-project (Submarine Groundwater Fluxes and Transport Processes from Methane Rich Coastal Sedimentary Environments), hydrogeology of the catchment area of the Eckernfoerde Bay within gehe whole Pleistocene succession down to the up-permost continous Tertiary aquitard was studied. This aquitard usually consists of clays of the Miocene Vierland-Stufe, which occur at 160 to 190 m bsl. Regional catchment areas of the most important aquifers and their main characteristics were estimated by evaluation of hydraulic and hydrochemical data from wells in this region. Groundwater in the Miocene aquifer in general is more reduced than groundwater in the Pleistocene aquifer, mainly due to the advanced activity of microorganisms. Recharge areas of the Pleistocene aquifer occur NW and S of Eckernfoerde, while recharge areas of the Miocene aquifer are situated in the SW of the study area and at the southern coast of the Eckernfoerde Bay. Some uncertainty arising from data aquisation at different times used in geostatistical regionalisation was accounted for by application of a fuzzy-kriging-procedure.     

珠江三角洲发展战略的思考——基于与长三角的比较

文章比较了珠江三角洲与长江三角洲的基本情况、经济发展差异,发现了珠三角的经济发展水平、发展效益高于长三角,但长三角的发展后劲足于珠三角;从改革开放政策、经济全球化以及内部矛盾等方面分析了形成上述差异的原因,在此基础上提出了“十一五”期间珠三角的以创新、拓展腹地与港澳合作等方面的发展战略导向。     

珠三角"城边工业旧村"的社区发展目标及路线初探——以深圳龙岗六联社区为例

珠三角城边工业旧村在行政上是一种城市社区,但与普通城市社区的社区发展目标不同,它需要通过社区发展加快社区的城市化进程.城边工业旧村具有边缘优势、相对优势和后发优势三大潜在优势,逐一实现这些优势就是其社区发展路线,当前应结合更新改造变"边缘效应"为边缘优势,避免演变为成熟的城中村.     

岭南活水——珠江三角洲水系景观地域特色探源

形成珠江三角洲水系景观地域特色的缘由主要有两方面,一是源于地理,二是源于文化。论文从自然地理、绿化、理水、人文等几方面较为详细地分析论证了三角洲水系景观地域特色的源由,为已全面展开的三角洲水系景观的更新改造提供基本理论依据。