A Study Of Water Resources Assessment And Groundwater Prospecting Methods For The Water Supply Project In The Hanzhong Section Of The Shiyan-Tianshui Freeway

The Shiyan-Tianshui Freeway is an important horizontal line in the "five horizontal seven longitudinal" system of National Highway Network Planning, which it plays an important role to promote the rapid economy development in Western China. The Hanzhong section of Shiyan-Tianshui Freeway in Shaanxi Pronvice across two hydrogeological zone of Hanzhong basin and Qinling mountain foothills, and there are great different in formation lithology, hydrogeological condition and so on. It brings out a difficulties and inconvenience for water supply project along the Freeway. Thus, the water supply project in the Hanzhong Section of the Shiyan-Tianshui Freeway was researched in this paper. Based on the analysis of engineering geology and hydrogeological condition, the aquifer position and watery degree were studied by induced polarization method. Meanwhile, the water inflows were calculated by using data of pumping tests, and the ground water quality was analyzed and evaluated. Based on the above research, the conclusions were following:(1) According to the apparent resistivity, the stratum was divided into three electrode layer. The apparent resistivity of granite and limestone layer is highest, the apparent resistivity of sandy cobble and sand layer is 25-54 ?.M and silty clay, mudstone and shale layer is 21-40 ?.M.(2) According to the IP sounding curve parameters, the thickness of Quaternary strata in Zhenpu toll station, Hanzhong Northern service area, Laodaosi parking area and Xinjiezi toll station is higher than 250 m, which there are belongs to the lot of groundwater mostly to partially. Meanwhile, the thickness of Quaternary strata in Mianxian toll station, Wuhou service area, Chadian toll station, Lueyang service area, Lueyang management and Shaanganjie toll station is 7-25 m, which there are belongs to the lot of groundwater partially to rarely.(3) The water inflow in Zhenpu toll station, Hanzhong Northern service area, Hanzhong Northern toll station, Baocheng toll station, Laodaosi parking area and Xinjiezi toll station is 3-70m3/h, which the water supply is dependence on tube wells. And the water inflow in Mianxian toll station, Wuhou service area, Chadian toll station, Lueyang service area, Lueyang management and Shaanganjie toll station is 0.288-20 m3/h. It could be use the large-caliber radiation wells.(4) The major ground water type along the Hanzhong Freeway is 1-A, wchich means the salinity M is no bigger than 1.5 1.5g/L and the hydrochemical type is HCO3-Ca. And ground water types in individual lots are 2-A(the salinity M is no bigger than 1.5 1.5g/L and the hydrochemical type is HCO3-Ca·Mg) and 4-A(the salinity M is no bigger than 1.5 1.5g/L and the hydrochemical type is HCO3-Ca·Na).(5) The p H of ground water type along the Hanzhong Freeway is 6.5-7.4 and the total hardness is 145.1-365.3 mg/L. In addition to the escherichia coli of biological indexes, the other indexes including physical indexes, the general chemical indexs and the toxicological index of ground water along the Hanzhong Freeway are accord with the rule of "Sanitary standard for drinking water"(GB5749-2006).