泰莱盆地地下水蓄水构造特征及勘查定井研究

针对基岩山区勘查定井问题,以旱区找水定井为目标,在地形地貌、地质和水文地质等实测资料的基础上,对泰安市地下水蓄水构造进行了分类,并阐述其特征。针对不同蓄水构造类型,基于构成地下水蓄水构造"三个基本要素"原理,并结合水文地质钻孔、高密度电阻率法、可控源音频大地电磁测深法等方法,对典型蓄水构造区构造特征及勘查定井进行了研究。结果表明:山东泰安市蓄水构造可分为水平岩层蓄水构造、断裂蓄水构造和基岩风化壳蓄水构造3种类型;水平岩层蓄水构造的含水层为古河道沉积砂层,隔水层为下伏古近系的泥岩和页岩,该区定井井位应布设在砂层上,井深宜在200 m左右,且应揭露砂层;断裂蓄水构造的含水层为奥陶系和寒武系白云岩和灰岩,隔水层为下伏的基岩岩层,导水通道为张性断裂带,在该区定井主要寻找奥陶系和寒武系地层,并尽量在断裂处或断裂交汇处定井;基岩风化壳蓄水构造的含水层为基岩风化壳,隔水层为下伏的基岩岩层,导水通道主要为张性断裂带,在该区定井主要是寻找基岩风化壳地层。

Study on characteristics of groundwater storage structures and well explorating and locating within Tailai Basin

Aiming at the well explorating and locating made in bedrock mountainous area and taking the well locating for finding groundwater within arid region as the study target，the groundwater storage structures within Taian Municipality are classified and their characteristics are expatiated herein on the basis of the measured data，such as topography，geology and hydrogeology，etc. Based on the principle of the“three basic structural elements”for constituting groundwater storage structure and combined with the methods of hydrogeological drilling，high density resistivity method，controlled source audio-frequency magnetotelluric sounding method，the structural characteristics and well explorating and locating within the typical regions of groundwater storage structures therein are studied for different types of groundwater storage structures. The study result shows that the groundwater storage structures within Taian Municipality of Shandong Province can be divided into three types，i. e. horizontal stratum groundwater storage structure，fault groundwater storage structure and bedrock weathering crust groundwater storage structure. The aquifer of the horizontal stratum groundwater storage structure is the sedimentary sandy layer of ancient river channel with the aquiclude of the underlying mudstone and shale of Paleogene System，for which the well location is necessary to be located on the sandy layer with the suitable well depth of about 200 mm，while the sandy layer therein is necessary to be exposed as well. The aquifer of the fault groundwater storage structure is consisted of Ordovician and Cambrian dolomite and limestone with the aquiclude of the underlying bedrock stratum and the water flowing channel of tensile fault zone，for which Ordovician and Cambrian strata are mainly to be necessarily found out for the well locating therein，while the well locating is appropriate to be tried to make at the location of fracture or the intersection of fractures. The aquifer of the bedrock weathering crust groundwater storage structure is bedrock weathering crust with the aquiclude of the underlying bedrock stratum and the water flowing channel mainly consisted of tensile fault zones，for which the bedrock weathering crust stratum is mainly to be necessarily found out for the well locating.