基于未确知测度理论的含水层富水性评价方法

含水层富水性分区是合理开发地下水资源的重要前提。为了解决传统富水性评价中过分依赖水文地质钻探资料以及影响因素的不确定性问题,以内蒙古荒漠草原典型煤矿为研究区,通过分析含水层富水性影响因素,结合大地电磁测深成果(MT)建立指标体系与分级标准。基于未确知测度理论的优势,利用模糊层次分析法与熵权法(FAHP-EW)组合确定指标权重,建立含水层富水性综合评价模型,并对研究区含水层富水性分区进行评价,借助地理信息系统(GIS)的空间信息融合功能将评价结果可视化。最后采用地面核磁共振(SNMR)技术验证评价结果的准确性。结果表明该方法对研究区富水性分区评价较为合理,证明该评价方法具有一定的有效性和实用性,可为荒漠草原含水层富水性评价提供方法借鉴。     

微透水岩体单孔抽水试验渗透系数的分析——以西非某水电站为例

抽水试验成本较高,耗时长,而单孔抽水试验获取的试验数据有限,且紊流、井损等因素对水位影响较大,从而影响参数计算精度;同时,实际抽水试验常在多种复杂边界条件下进行,如试验孔有临河时,需结合多种含水层模型,使实际抽水试验条件尽可能与理论模型条件相近,选择合适的模型计算,相互比较验证,求取岩土体渗透系数;将计算成果与有其他水文地质试验结果比较,综合确定渗透系数,进一步提高了岩土体渗透系数的合理性。     

刘家峡水电站坝基承压水水位突降原因分析

介绍了刘家峡坝基承压水力突降情况,分析了承压水变化规律,揭示了承压水位突降是由于裂隙突然张开或裂隙的某一部位突然与相邻的上部裂隙潜水渗流或排水通道相连通造成的,阐明承压水与裂隙潜水的连通一般对大坝的安全不会构成威胁的观点。     

New Methodology for Optimal Operation of Soil Aquifer Treatment Systems

A new methodology is presented in thisarticle for computing the optimal operation of soilaquifer treatment systems. The mathematical problemis stated as a discrete-time optimal control problemto maximize infiltration subject to various physicaland operation constraints. The methodology is basedupon solving the discrete-time optimal control problemusing a successive approximation linear quadraticregulator interfaced with a simulator. Theunsaturated flow model HYDRUS is modified to simulatethe water content distribution, the infiltrationprocess, and the draining process. A penalty functionmethod is used to treat the bound constraints on thewater content and the cycle time. Sample problems aregiven to illustrate the capability of the model tosolve the optimal operation of soil aquifer treatment systems.     

不同止水帷幕插入深度下基坑降水对周边环境的影响预测分析

我国沿江沿海地区地下承压水分布特征及水文地质条件复杂,该地区基坑降水对周边环境的影响预测分析是技术难题。为研究不同止水帷幕插入深度下坑外地表沉降和坑外水位降深对坑内降水的响应特征,本文以常州地铁2号线某深基坑工程为例,采用有限元软件ABAQUS建立了基坑降水三维分析模型。结果表明:随着止水帷幕插入比的增大,基坑降水对周边环境的影响范围逐渐减小。定义止水帷幕插入承压含水层深度占其层厚的比值为插入比,当止水帷幕插入比小于1/2时,降水对坑外环境影响较大;当止水帷幕插入比大于3/4时,其止水效果与止水帷幕完全隔断承压含水层时接近,降水对坑外环境影响很小。研究成果为该地区地铁车站基坑止水帷幕优化设计提供良好的理论依据。     

Determining Hydraulic Characteristics of Production Wells using Genetic Algorithm

Proper well management requires the determination of characteristic hydraulic parameters of production wells such as well loss coefficient (C) and aquifer loss coefficient (B), which are conventionally determined by the graphical analysis ofstep-drawdowntest data. However, in the present study, the efficacy of a non-conventional optimization technique called Genetic Algorithm (GA), which ensures near-optimal or optimal solutions, is assessedin determining well parameters from step-drawdown test data. Computer programs were developed to optimize the well parametersby GA technique for two cases: (i) optimization of B and C only, and (ii) optimization of B, C and p (exponent) as well as to evaluate the well condition. The reliability and robustness of the developed computer programs were tested usingnine sets of published and unpublished step-drawdown data from varying hydrogeologic conditions. The well parameters obtained by the GA technique were compared with those obtained by the conventional graphical method in terms of root mean square error(RMSE) and visual inspection. It was revealed that the GA technique yielded more reliable well parameters with significantlylow values of RMSE for almost all the datasets, especially in caseof three-variable optimization. The optimal values of the parametersB, C and p for the nine datasets were found to range from 0.382 to 2.292 min m^-2, 0.091 to 3.262, and 1.8 to 3.6, respectively. Because of a wide variation of p, the GA techniqueresulted in considerably different but dependable and robust well parameters as well as well specific capacity and well efficiency compared to the graphical method. The condition of three wells was found to be good, one well bad and that of the remaining five wells satisfactory. The performance evaluation of the developed GA code indicated that a proper selection of generation number and population size is essential to ensure efficient optimization. Furthermore,a sensitivity analysis of the obtained optimal parameters demonstrated that the GA technique resulted in a unique set ofthe parameters for all the nine datasets. It is concluded thatthe GA technique is an effective and reliable numerical tool for determining the characteristic hydraulic parameters of production wells.     

耐高温无机聚合物胶结材料的开发研究

研究尝试以无机聚合物取代环氧树脂进行可行性实验,在实验过程中发现无机聚合物容易产生干缩裂缝,且与碳纤维的胶合、围束性能较弱,同时经高温(700~800℃)定压加温之后碳纤维呈现碎裂现象。但经检讨其在围束补强后定载加温模式,确实较现行以环氧树脂作为胶合补强材料有较高的抗温行为。为寻求更适合的取代物,尝试以玻璃纤维替代碳纤维作为围束补强材料的可行性实验,克服前述干缩裂缝缺点,以及探求无机聚和物厚度与热传导的关系。     

地下水水位对饱和砂土震动液化判定的影响

结合荆州市某商业广场地基工程实例,从标准贯入试验、静力触探试验、剪切波速试验和计算等方面就地下水水位对饱和砂土震动液化判定的影响等问题进行论证分析。建议取承压水水头深度作为地下水水位深度来进行饱和砂土震动液化的判定。     

A geostatistical methodology to estimate the base of the Trifa aquifer (Morocco) with limited drilling and geo-electrical sounding data

The paper presents the methodology used to estimate the base and thickness of the Trifa aquifer, north-east Morocco, from very limited drilling and geoelectrical sounding data. The methodology is applicable where the aquifer is a single horizon with considerable lateral variation. The procedure is based on geostatistical techniques: kriging of apparent resistivities, calibration of the resistivities with information from drilling, co-kriging of resistivities and estimation of the thickness of the aquifer by inverting the apparent resistivity formula. Calculated and measured substratum levels are obtained by subtracting the estimated and measured thickness from the topography at the drilling and geo-electrical sounding locations. By co-kriging the estimated substratum levels with the measured values in the drilling locations, a map of the substratum over the plain was prepared.     

一栋住宅楼的纠倾

介绍了一幢拟建 6层 ,当建至 4层时倾斜已超限的多层建筑纠倾工程。本工程采用排式竖向钻孔挤土技术 ,合理利用待施工的两层作为纠偏荷重组合 ,最终将挤土孔在基础周边构成树根桩 ,起到围箍、稳定地基、限制变形发展与提高地基承载力的效果。是多种方法组合应用的成功实例