Identifying environmental impacts of underground construction

Dewatering of the groundwater resource and associated reduced flow of surface water features are potential negative impacts when constructing underground facilities. Little work has been done to develop methods for the early detection of environmental impacts on water resources where major underground construction is being undertaken. Recognizing this, prior to construction of two rock tunnels in the southwestern USA, a 3-year preconstruction program was implemented to monitor over 100 wells, springs, and streams in the project area that might be affected. This preconstruction monitoring phase has established data for a hydrologic reference which indicates a high degree of spatial and temporal variability. This variability must be accounted for when trying to identify construction-related impacts. The project area was subdivided into areas of similar characteristics based on geologic and hydrologic features. Measurements from features within each unit were then normalized and aggregated to derive a single representative flow parameter. This representative flow was then correlated to precipitation and major stream flow records to allow for a method of estimating unimpacted flow and groundwater levels during and after construction. Application of this method proved useful in determining and enabling a quick response to construction-related impacts.     

城市地下管线横断面的设计与绘制

地下管线横断面图是反映地下管线探测成果的重要手段,对于施工、设计、管理都有着非常现实的指导意义。本文主要阐述了横断面图的设计原理以及运用VBA语言通过对AUTOCAD2008进行二次开发,实现地下管线横断面图的自动绘制。     

黄河三角洲南部冲洪积扇区地下淡水调蓄条件研究

黄河三角洲南部冲洪积扇区浅层地下水由于长期大量开发利用,早已形成了区域性漏斗群。通过对漏斗区地下水赋存条件和调蓄条件的分析,提出了由新建的引黄主干渠引黄河水,采用河渠、坑塘内施工回灌引渗,以及丰水期大气降水地表径流拦蓄引渗和引黄河水引渗回灌联合调度的方案,并从调蓄资源增量、调蓄可行性和调蓄效益等方面进行了论证。     

我国地震地下流体科学40年探索历程回顾

通过回顾40年来中国大陆地震地下流体科学研究与实践的发展历程,总结了早期在该领域具启迪性的研究工作和主要成果。纵观历史,无论是观测技术和理论方法的创新,还是对各种参量的观测分析以及预测方法的研究,地震地下流体科学都与地震监测预报这一关键需求紧密相关。地下流体观测网建设的历史沿革表明,对强地震的监测与预测需求推进了观测网的建设和发展;观测技术的发展过程体现出基于多手段、综合性和数字化的趋势;地下流体理论与前兆机理的研究成果表明,前兆模型(或模式)、数值模拟、室内和野外实验研究等是推进学科创新工作的主要技术途径;地震预测方法的研究成果体现出探索基于具有物理基础的预报技术,以及重视实用性与科学性相统一的思想;预测实践证明,地下流体学科在我国大陆地震预测实践中发挥着重要作用。文章最后介绍了本学科主要的论著及技术规范,简要回顾了不同的历史发展阶段、有关学术团体和专家对地下流体学科主要科学问题的认识以及该学科的重点发展方向。     

地震地下流体数字化观测初探

“九五”期间，中国地震局在山东聊城水化站对地下流体学科数字化改造的7种仪器进行了试验，并于1999年11月通过验收，现已运行3a。为全面总结上述7种数字化仪器的运行情况，对各类仪器的优缺点做了综合评定，同时对多种数字化记录资料与模拟记录资料进行了对比分析，得出SD－3A型测氢仪、GWK－201型测氦仪、LN－3数字式水位仪工作性能较稳定、测值连续准确可靠的结论。     

岩溶地区地下河系统水资源定量评价的问题与出路

岩溶地区含水介质的多重性和高度复杂性,给地下河系统的水资源量评价带来许多难题。在分析地下河系统水资源形成、分布和运移特征基础上,认为目前用于地下水评价的主要方法都不太适用来解决地下河系统水资源量的评价和预测问题。作者在比较地下河与地表水多方面的相似性后,建议引入现代水文学的理论方法和模型来解决岩溶地区地下河系统水资源评价问题,并分析了可能需要解决的若干关键问题。针对岩溶水资源的特征,作者认为,改变传统定量评价的思维、引进现代水文学理论方法和充分利用3S技术,是解决地下河系统水资源定量评价的主要出路。      

某水电站地下洞室随机块体稳定性评价及系统锚固设计

地下洞室中的随机块体是指由岩体中的随机节理或者基体裂隙构成的不确定性块体 ,在已建的地下厂房中 ,这类块体大量存在 ,这类块体的稳定性会对洞室的施工安全造成较大的影响。在设计中这类块体常常是通过系统锚杆进行加固 ,但由于块体位置随机性和几何特征的不确定性 ,使得系统锚杆的长度和间距很难确定。本文以某水电站的地下洞室为研究对象 ,在深入了解地质条件、岩体结构特点的基础上 ,找出可能构成随机节理的分布规律 ,再分析节理与节理、节理和Ⅰ、Ⅱ类确定性结构面可能的组合 ,得到可能的随机块体 ,然后采用块体理论评价其稳定性 ,得到随机块体的几何特征和稳定状况 ,总结出最优的锚杆长度 ,为地下洞室的系统锚杆长度的确定提供了理论依据     

某大型地下洞室群围岩稳定性分类研究

根据地下洞室群的特点 ,选取岩体质量综合级别、块体状况、开挖位移及破坏区、岩爆烈度四因素为分类指标 ,建立了大型地下洞室群围岩稳定性分类体系。针对不同稳定性等级 ,提供了相应的开挖方式和支护处理建议。最后 ,运用该分类体系对某地下洞室群的主厂房进行了分析评价。     

Sulphate generation in South African underground and opencast collieries

Deterioration in the water quality results from coal mining, and the significant impact on the environment in South Africa has been reported (Funke in SA Water, Sci Technol 15:115–144; 1983). Pyrite in with South African coal can be oxidised to yield acidic and high salinity water. This study deals with the rate at which sulphate could be produced for collieries under different conditions. Four collieries in the Witbank coalfield were selected for this investigation. The boreholes were investigated with an in-situ multi-parameter probe, and then sampled at different times with a specific depth sampler to determine the chemical composition of the water in the collieries. Water level measurements and volumetric calculations were done to determine influx rates. Daily sulphate generation rate for underground mining was found to be in the range of 0.4–2.7 kg/ha, depending on the availability of oxygen and the residence time of the water (the time available for neutralising agents present to react) in the mining void. The exclusion of oxygen due to flooding and the presence of calcareous carbonates influences the observed sulphate generation.     

The LUSI mud volcano triggering controversy: Was it caused by drilling?

Following the Yogyakarta earthquake on May 27th, 2006, the subsequent eruption of a mud volcano has been closely observed and analyzed by the geological community. The mud volcano, known as LUSI, began erupting near the Banjarpanji-1 exploration well in Sidoarjo, East Java, Indonesia. LUSI offers a unique opportunity to study the genesis and development of a mud volcano.