某水垫塘排水主洞渗(漏)水快速处理施工技术

以西南地区某高拱坝坝后水垫塘排水主洞渗(漏)水快速处理为例,介绍了在复杂边界条件下排水主洞渗(漏)水快速处理的材料选择、施工工艺,供参考。

Water and Heavy Metal Transport in Roadside Soils

Roads with very high traffic loads in regions where soils are low in both pH and sorption capacity might be a source of percolation water loaded with heavy metals. Looking at some "worst case" scenarios, this study focused on the input of traffic related pollutants and on Pb, Cd, Cu, Zn, Ni and Cr concentrations in the soil matrix and soil solution, respectively. The analysis also included pH and electrical conductivity and at some sites DOC. The investigations were carried out on sandy soils with more or less low pH values at four motorway sites in Germany. The average of daily traffic was about 50 000 up to 90 000 vehicles. Soil pore water was collected in two soil depths and at four distances from the road. The pH in general decreased with increasing distance from the roadside. The elevated pH near the roadside was presumably caused by deposition of dust and weathering residues of the road asphalt, as well as by infiltration of salt that was used during winter time. At these road sites, increased heavy metal concentrations in the soil matrix as well as in the soil solution were found. However, the concentrations seldom exceeded reference values of the German Soil Protection Act. The soil solution concentrations tended to increase from the road edge to 10 m distance, whereas the concentration in the soil matrix decreased. Elevated DOC concentrations corresponded with elevated Cu concentrations but did not substantially change this tendency. High soil water percolation rates were found near the roads. Thus, even low metal concentrations of percolation water could yield high metal loads in a narrow area beside the road.

Analysis of the Harmfulness of Water-Inrush from Coal Seam Floor Based on Seepage Instability Theory

A theory of seepage instability was used to estimate the harmfulness of water-inrush from a coal seam floor in a particular coal mine of the Mining Group,Xuzhou. Based on the stratum column chart in this coal mine,the distribu-tion of stress in mining floors when the long-wall mining was respectively pushed along to 100 m and to 150 m was simulated by using the numerical software (RFPA2D). The permeability parameters of the coal seam floor are described given the relationship between permeability parameters. Strain and the water-inrush-indices were calculated. The wa-ter-inrush-index was 67.2% when the working face was pushed to 100 m,showing that water-inrush is possible and it was 1630% when the working face was pushed to 150 m,showing that water-inrush is quite probable. The results show that as long-wall mining is pushed along,the failure zone is enlarged,the strain increased,and fissures developed cor-respondingly,resulting in the formation of water-inrush channels. Accompanied by the failure of the strata,the perme-ability increased exponentially. In contrast,the non-Darcy flow β factor and the acceleration coefficient decreased ex-ponentially,while the increase in the water-inrush-index was nearly exponential and the harmfulness of water-inrush in the coal mine increased accordingly.

Crack propagation mechanism of compression-shear rock under static-dynamic loading and seepage water pressure

To reveal the water inrush mechanics of underground deep rock mass subjected to dynamic disturbance such as blasting, compression-shear rock crack initiation rule and the evolution of crack tip stress intensity factor are analyzed under static-dynamic loading and seepage water pressure on the basis of theoretical deduction and experimental research. It is shown that the major influence factors of the crack tip stress intensity factor are seepage pressure, dynamic load, static stress and crack angle. The existence of seepage water pressure aggravates propagation of branch cracks. With the seepage pressure increasing, the branch crack experiences unstable extension from stable propagation. The dynamic load in the direction of maximum main stress increases type I crack tip stress intensity factor and its influence on type II crack intensity factor is related with crack angle and material property. Crack initiation angle changes with the dynamic load. The initial crack initiation angle of type I dynamic crack fracture is 70.5°. The compression-shear crack initial strength is related to seepage pressure, confining pressure, and dynamic load. Experimental results verify that the initial crack strength increases with the confining pressure increasing, and decreases with the seepage pressure increasing.

Water Losses in Arid and Semi-Arid Zone:Evaporation, Evapotranspiration and Seepage

The primary purpose of this study was to assess water losses by evapotranspiration, evaporation and seepage in arid zone.Normally, evaporation and seepage are the main causes of water losses.For modeling water losses,a combination of Genetic Programming(GP),Penman-Monteith(PM) and Penman combination model for measurement of evapotranspiration,evaporation and seepage has been developed.The results were found to be varying depending on how the evaporation and seepage phenomena are modeled.These results show that that there is an improvement in reducing evapotranspiration,evaporation and seepage losses in arid and semi-arid region.

Movement characteristics of Karst water in a deep mining area

In order to study the movement characteristics of groundwater in a deep mining area and solve the dispute of the distri- bution rule of hydro-chemical zoning which is contradicted by lixiviation water zoning in a horizontal direction, we directed our attention to the source of deep groundwater, its seepage and hydro-chemical characteristics in a typical mining area. We used a neotectonic water-control theory, chemical and isotope methods, as well as a method for analyzing dynamic groundwater conditions. The results indicate that 1) Karst water in the deep and medium parts of this mining area is recharged by vertical leakage through neotectonic fractures rather than seepage along strata from subcrop parts or surrounding flows; 2) from surface to deep leakage paths, the variation in the types of chemical groundwater agrees with the normal lixiviation water distribution rule and the age of mixed groundwater increases; 3) the water-rich zones along neotectonic fractures correspond with water-diluted zones in a hori-zontal direction; 4) the leakage coefficient and water capacity of aquifers increases during the flow process of Karst water along the antidip direction (from west to east) and 5) Karst water in shallow mining areas forms a strong runoff belt along strikes and quickly dilutes the water from deep and medium mining areas. Overall, chemical and dynamic water characteristics actually agree with in terms of the entire consideration for differences in vertical leakage and abnormalities in the zone of water chemical distribution, along a horizontal runoff direction.

Application of Chemical Tracing Experiment Technique in Leakage Detection of Hydraulic Engineering

[Objective] The research aimed to study the application of chemical tracing experiment technique in leakage detection of hydraulic engineering.[Method] According to the current situation of Sanyuan Western Suburb Reservoir in Xianyang City of Shaanxi Province,three sections （L1,L2 and L3） were set.KI was selected as the chemical tracer to carry out the tracing and detection research.[Result] There was no obvious leakage phenomenon in L1,L2 and L3 sections.The impermeability of rock in some dam abutments was bad.[Conclusion] The leakage reason of Western Suburb Reservoir was that the impermeability of rock in some dam abutments couldn’t satisfy seepage requirement.After the reservoir was put into operation,the water level in front of dam rose,and the ground water level of dam abutment also rose.The penetration water pressure correspondingly increased,and the water content of bank slope at the downstream of dam increased.

Study on the law of methane seepage in the wall of drainage roadway in mining seam-group

Based on the equation of the gas flow continuity and state, Darcy law and Langmuir equation, the law of methane seepage in the wall of drainage roadway was studied. The governing equation of methane one-way seepage in the seam was founded. By solving the equation, the calculation of methane seepage velocity in the coal wall was worked out. The result has really applied worth and will give beneficial references to re-lated research, it provides preventing coal and gas outbursts with theoretical gist.

Research on sustainable exploration of the geothermal water in Xiaoquan area

On the basis of discussion about hydro-geologic condition of geothermal water in Xiaoquan area, Chongqing, a three-dimensional mathematical model was established. The Modflow(a modular three-dimensional finite-difference groundwater model) software was adopted to simulate the geothermal water, and quantificational study on sustainable exploration of the geothermal water in Xiaoquan area was carried out. Firstly, a mathe- matical model was set up. Then, the geothermal water was simulated by Modflow software, and the mathematical model was identified. The simulative water level was compared with the actual water level and the mathematical model was calibrated. The feasibility of appli- cation of this mathematical model to studying underground geothermal water was proved that the simulative water level is approximated to actual one, and a right mathematical model was obtained. This mathematical model was used to simulate geothermal water under different exploitation conditions, at last the yields of sustainable exploitation includ- ing the maximum yield and the optimal yield were determined.