高密度电阻率法在金凤煤矿水文地质探测中的应用

煤矿防治水工作对煤矿安全开采非常重要,查明矿井水文地质情况是煤矿防治水工作的重要内容之一.利用高密度电法对金凤煤矿011802工作面进行勘探,提出了高密度电阻率法在解决煤矿含水层富水性划分及地下水通道导水性评价的方法,查明了古近系、基岩风化带的相对富水区,取得了较好的验证效果,说明高密度电阻率法能很好地解决此类水文地质勘查问题.     

含水层失水与岩溶塌陷引起的采动损害分析

分析采矿活动对地表损坏的原因.得出了以含水层失水与岩溶塌陷为主、开采直接影响为辅的采动损害结论.研究结论为南方岩溶发育地区开采损害预计和责任认定提供了依据.     

承压水体上开采底板岩层破断及渗流特征

以山西某煤矿承压水体上下组煤开采为工程背景,通过对煤层底板岩石进行全应力-应变渗透性试验及单裂隙渗透性试验,揭示了岩石应力-渗流耦合机理,获得了断裂面渗透系数的定量关系式;采用离散元流固耦合模拟方法,对承压水体上煤层开采底板岩层的应力状态及渗流特征进行模拟分析.结果表明:底板岩层"四带"中的渗透性均与水平应力密切相关,其中:直接底板受工作面矿压影响严重,岩层中的水平应力杂乱无章,破坏带厚度约13m;奥灰含水层顶部岩层为低围压区,容易形成奥灰水楔劈裂导升机理,导升带厚度为17m左右;底板中部层位受采动矿压及底板承压水直接影响相对较小,此带中水平应力自上而下呈递增状态,有效隔水层带厚度38m,是底板的关键阻水层.     

多孔介质含水层疏水引起的地表下沉研究

研究含水层疏水及采矿引起的地表下沉对地面建（构）筑物的保护有重要意义。本文以孔隙弹性理论为基础,对多孔介质含水层疏水引起的地表下沉进行了分析,同时应用有限元方法耦合计算了多孔介质含水层疏水及采矿引起的地表下沉。     

典型城市承压含水层区域性特性

为了避免基坑工程设计和施工中因没有处理好承压水影响而产生的基坑工程事故,研究承压含水层特性.以调查研究杭州钱塘江承压含水层特性为主,参考上海、武汉、北京、天津4个城市有关水文地质方面的研究材料,研究这5个城市的承压含水层特性.比较分析这5个城市的承压含水层埋深、厚度、水位、顶板厚度等特性,介绍各城市典型的工程实例、承压水处理方法及抽降承压水对地面沉降的影响.研究表明:杭州、上海两地潜水与承压水的越流效果不明显,可视条件选择全降水或隔渗帷幕结合减压降水;武汉地区承压含水层埋藏浅,上层承压水可以采用疏干的方法;北京、天津两地单层含水层和隔水层厚度较小,可以尝试自渗降水.     

Characteristics of water inflow and chemical grouting treatment of a Liu Yuanzi Coal Mine shaft in the Ordos Basin

During shaft constructing, a borehole water inflow of 30 m3/h was encountered in Liu Yuanzi Coal Mine in the southwestern Ordos Basin, whose aquifer is mainly cretaceous. On the basis of regional hydrogeological conditions, a mercury intrusion method and scanning electron microscope were used in this study. We conclude that the loose, porous and easily collapsible clay particles of the cretaceous aquifer rock mass were the major geological cause for water hazards during the construction of the shaft. We propose an approach of chemical grouting from the working surface and in the end succeeded in blocking the water.     

Fuzzy vulnerability mapping of urban groundwater systems to nitrate contamination

The aim of this study is to develop a new fuzzy optimization model to find the optimal factor weights of modified DRASTIC index for groundwater vulnerability mapping an urban aquifer to nitrate contamination. Eight factors including water table depth, recharge, aquifer media, soil media, topography, impact of vadose zone, hydraulic conductivity, and land use are considered and rated. A fuzzy linear regression is formulated between the values of eight factors and corresponding nitrate concentration in groundwater. An optimization model based on real code genetic algorithm with objective of minimizing the sum of the fuzzy spread of the regression coefficients is implemented. Aquifer of Mashhad metropolis (northeast of Iran) is chosen to evaluate the proposed model. The results show the proposed model is a promising tool for weighting the factors with avoiding the subjectivity and also ambiguities accompanied by parameters to produce an accurate specific vulnerability mapping of an urban aquifer.     

Comparative Analysis of Soil Water and Salt Dielectric Model

The soil dielectric constant,the basis of the microwave remote sensing inversion of soil water and salt,is one of the main parameters of microwave remote sensing research.It is very important to select the high precision soil water and salt dielectric model to improve the precision of soil water and salt inversion.However,the existing soil water and salt model still can’t quantitatively describe the effect of salt factor on soil permittivity.This paper simulates the complex permittivity of different texture,water content and salinity wet soil by Dobson model,Dobson|S model,GRMDM model,HQR model and WYR model at L,Cand X bands when soil temperature equal 25 ℃.Comparison and analysis the simulation values with measured values by microwave vector network analyzer.The results show：(1)Dobson model and GRMDM model can accurately simulate the real part of dielectric constant of non|saline soil,while the stimulated values of imaginary part is less than the measured values;(2)Dobson|S model can well simulate the real part of the dielectric constant of saline soil,at L,Cnd Xbands the correlation coefficient R equal 0.97,the RMSE is less than 2.10.But for the imaginary part of the dielectric constant of saline soil,the Dobson|S model,HQR model and WYR model with different simulation accuracy,when soil water content different.This study would benefit the choice of a suitable soil dielectric model for soil moisture and salinity retrieval.     

北疆盐碱地采用生物措施后的土壤盐分变化

本文是地下水位3~5m、壤土质地条件下盐碱地长期生物改良田间试验的结果,结果表明:种植耐盐冬小麦套播草木樨是最好的脱盐方式,经过1年, 1m土层平均盐分由1 989%降到0 282%,脱盐率达85 82%;种植耐盐牧草套播草木樨、苜蓿是比较好的脱盐方式:经过3年, 1m土层平均盐分由1 34%降到0 524%,脱盐率60 90%;密植枸杞4年后, 1m土层平均盐分由2 363%降到0 800%,脱盐率为66 14%,适应于盐分特别高的土壤改良;施有机肥种植作物(植物)灌溉,是完善的改良盐碱地方法,一方面,在灌溉水作用下盐分被淋溶,另一方面在有机肥作用下,降低了0 ~40cm土层残余HCO-比例。15年盐碱地改良与利用证明:脱盐后的土地利用时,需考虑深根与浅根、多根与少根作物的适配轮作,以免导致土壤上层盐分回升;未施有机肥的高度脱盐,可能引起土壤上层碱化,即残余HCO-比例很大。     

Development of a linear predictive model for carbon dioxide sequestration in deep saline carbonate aquifers

CO₂ injection into deep saline aquifers is a preferred method for mitigating CO₂ emission. Although deep saline aquifers are found in many sedimentary basins and provide very large storage capacities, several numerical simulations are needed before injection to determine the storage capacity of an aquifer. Since numerical simulations are expensive and time-consuming, using a predictive model enables quick estimation of CO₂ storage capacity of a deep saline aquifer. In order to create a predictive model, the ranges of variables that affect the CO₂ storage capacity were determined from published literature data. Correlations found in literature were used for other important parameters such as pore volume compressibility and density of brine. Latin hypercube space filling design was used to construct 100 simulation cases prepared using CMG STARS. The simulation period covered a total of 300 years of CO₂ storage. By using a least-squares method, linear and nonlinear predictive models were developed to estimate CO₂ storage capacity of deep saline carbonate aquifers. Numerical dispersion effects were considered by decreasing the grid dimensions. It was observed that a dimensionless linear predictive model is better than the nonlinear. The sensitivity analyses showed that the most important parameter that affects CO₂ storage capacity is depth. Most of the (up to 90%) injected gas dissolved into the formation water and a negligible amount of CO₂ reacted with carbonate.