高密度电阻率成像法在古河道型地下水库工程中的应用研究
发布时间：2018-12-25 12:21
【摘要】：古河道型地下水库是开发利用古河道浅层淡水基础上发展起来的,其试图人为利用古河道砂体作为调蓄库容,增加可利用水资源量。在冲积平原地区,古河道通常是地下水储存和运移的主要通道,对于建设地下水库而言,古河道为调蓄水资源,进行地下水回灌,修复地下水位起到关键性作用。弥河下游冲洪积扇内因来水量平枯不均,地表水拦蓄工程较少,致使地表水利用率较低,区域内地下水超采严重,地下水位大幅下降,现已形成多个区域性大型漏斗区,加之北部咸水水头与区域内淡水水头差日益增大,依托古河道良好的地层条件,北部咸水向内陆含水层的入侵现象愈发严重。为缩减地下水漏斗区,抬升区域地下水位,利用地下坝体阻止咸水入侵、阻截淡水入海,现拟借助古河道中沉积的砂、砾石等多孔介质作为储水空间来建设地下水库,并引调地表水体进行蓄灌,从而防止北部咸水的进一步入侵。因此对于库区内古河道结构的研究是建设古河道型地下水库的一项重要内容,古河道位置、埋藏深度及厚度等特征的查明可为地下水库建设的位置、规模、结构及地下防渗墙关键技术参数等研究提供依据。本论文主要研究内容及工作量如下:(1)通过收集弥河下游冲洪积扇地区的地形地貌、水文地质、钻孔岩性记录及粒度分析等资料,查明研究区内古河道形成与发育条件及岩性等特征参数,明确古河道的分布特征和富水性动态变化特征。(2)根据现场地电条件,在研究区布置32条东西向高密度电阻率成像数据采集测线进行扫描测量,每条测线长378m,测线西起台头镇付家庄村,东到田柳镇王高八村以东,全长12096m;并在能反映古河道砂层存在的测线中采集24个测深点进行电测深曲线绘制,获得岩体电特性参数信息;(3)将采集的野外实验数据进行数据预处理、反演计算及绘图等工作,得到二维高密度电阻率图像和电测深曲线图,重点从电阻率电特性参数分析岩体的空间结构特征,研究古河道位置、埋深等信息。通过以上研究,取得了如下研究成果:(1)研究区内古河道整体上是以高阻值电阻率体现,在未固结成岩区其电阻率值在20-40Ω·m范围内,岩性以细砂、粉细砂为主,在局部固结成岩区,电阻率值可达几百欧姆·米;围岩以低阻值电阻率体现,电阻率值在0-20Ω·m范围内,岩性以地表覆盖土层和黏土层为主。(2)基于二维高密度电阻率图像分析,该段古河道呈WS—EN走向,东西宽约1400m,东西岸位置较明确;砂层在河道中段埋藏深度较大,两端埋藏深度较小,呈大“U”字型分布,该分布极具典型河床特性,砂层厚度横向变化符合古河床动力学产物特征;砂层周边解译出残留黏土块堆积,黏土块的存在有的对砂层的堆积有明显的制约作用,有的促使形成良好的砂层沉积区,为进一步明确古河床沉积的形态和规律具有重要意义。(3)基于电测深曲线分析,古河道富集带电阻率值整体呈三段走势,表层电阻率值大多呈缓平或下降趋势,判断为黏土覆盖层;中间曲线呈上升趋势,电阻率值增加,判断为砂层反映;底部曲线缓平或下降,判断多为黏土层或砂质黏土和粘质砂土。
[Abstract]:The ancient channel type underground reservoir is developed on the basis of the development and utilization of the shallow fresh water of the ancient river channel, which is an attempt to make the use of the ancient river sand body as the storage capacity and increase the amount of available water resources. In the alluvial plain area, the ancient river channel is usually the main channel of underground water storage and migration. For the construction of the underground reservoir, the paleochannel is a key role in regulating the water resources, carrying out groundwater recharge and repairing the groundwater level. The internal cause of water and water in the alluvial fan in the lower reaches of the Yuhe River is uneven, and the surface water retaining works are less, so that the utilization of surface water is low, the groundwater in the area is extremely serious, the groundwater level is greatly reduced, and a plurality of regional large-scale funnel areas are formed. In addition, the difference of fresh water head in the water head of the north and the water head in the area is increasing, and the intrusion of the salt water to the inland aquifer becomes more serious depending on the favorable formation conditions of the ancient river channel. in ord to reduce that water level of the underground water funnel and raise the groundwater level of the area, the underground dam body is utilized to prevent the salt water intrusion, the water is intercepted and the fresh water enters into the sea, and the underground reservoir is constructed by using a porous medium such as sand and gravel deposited in the old river channel as a water storage space, and the surface water body can be used for storage and irrigation, so as to prevent the further invasion of the northern brackish water. Therefore, the research on the structure of the ancient river channel in the reservoir area is an important part of the construction of the ancient channel type underground reservoir, which can provide the basis for the research of the location, scale, structure of the underground reservoir and the key technical parameters of the underground anti-seepage wall. The main contents and workload of this thesis are as follows: (1) The characteristics of the formation and development conditions and the lithology of the paleochannel in the study area are identified by collecting data such as the topography, the hydrogeology, the drilling lithology and the grain size analysis of the alluvial fan area in the downstream of the Yuhe River. The distribution characteristics and the water-rich dynamic characteristics of the ancient river channel are defined. (2) According to the on-site electrical conditions, 32 east-west high-density resistivity imaging data acquisition and measurement lines are arranged in the study area for scanning and measurement, and the length of each test line is 378m, and the west of the line of measurement is in the village of Jiazhuang, and the east to the east of the eight-village-high-eight village in the town of Liuliu Town, and the total length is 12096m; and collecting 24 sounding points in the measuring line which can reflect the existence of the sand layer of the ancient river, and drawing the electric sounding curve to obtain the parameter information of the electrical property of the rock mass; and (3) carrying out data preprocessing, inversion calculation and drawing and the like of the collected field experimental data, A two-dimensional high-density resistivity image and an electric sounding curve are obtained, and the spatial structure characteristics of the rock mass are analyzed, such as the location of the ancient river channel, the depth of the burial, and the like. Through the above research, the following research results have been obtained: (1) The whole river channel in the study area is characterized by high resistance, and the resistivity value of the unconsolidated diagenetic area is in the range of 20-40惟 路 m, and the lithology is dominated by fine sand and fine sand, and in the local consolidation diagenetic area, The resistivity value can reach a few hundred ohms 路 m; the resistivity of the surrounding rock is represented by low resistance, and the resistivity value is in the range of 0-20 惟 路 m, and the lithology is dominated by the surface covering soil layer and the clay layer. (2) Based on the two-dimensional high-density resistivity image analysis, the paleochannel of this section is in the direction of WS-EN, the east and west is about 1400m, and the location of the east and west is clear; the depth of the sand layer in the middle of the channel is large, the buried depth of the two ends is small, and the large-鈥淯鈥，
本文编号：2391110
[Abstract]:The ancient channel type underground reservoir is developed on the basis of the development and utilization of the shallow fresh water of the ancient river channel, which is an attempt to make the use of the ancient river sand body as the storage capacity and increase the amount of available water resources. In the alluvial plain area, the ancient river channel is usually the main channel of underground water storage and migration. For the construction of the underground reservoir, the paleochannel is a key role in regulating the water resources, carrying out groundwater recharge and repairing the groundwater level. The internal cause of water and water in the alluvial fan in the lower reaches of the Yuhe River is uneven, and the surface water retaining works are less, so that the utilization of surface water is low, the groundwater in the area is extremely serious, the groundwater level is greatly reduced, and a plurality of regional large-scale funnel areas are formed. In addition, the difference of fresh water head in the water head of the north and the water head in the area is increasing, and the intrusion of the salt water to the inland aquifer becomes more serious depending on the favorable formation conditions of the ancient river channel. in ord to reduce that water level of the underground water funnel and raise the groundwater level of the area, the underground dam body is utilized to prevent the salt water intrusion, the water is intercepted and the fresh water enters into the sea, and the underground reservoir is constructed by using a porous medium such as sand and gravel deposited in the old river channel as a water storage space, and the surface water body can be used for storage and irrigation, so as to prevent the further invasion of the northern brackish water. Therefore, the research on the structure of the ancient river channel in the reservoir area is an important part of the construction of the ancient channel type underground reservoir, which can provide the basis for the research of the location, scale, structure of the underground reservoir and the key technical parameters of the underground anti-seepage wall. The main contents and workload of this thesis are as follows: (1) The characteristics of the formation and development conditions and the lithology of the paleochannel in the study area are identified by collecting data such as the topography, the hydrogeology, the drilling lithology and the grain size analysis of the alluvial fan area in the downstream of the Yuhe River. The distribution characteristics and the water-rich dynamic characteristics of the ancient river channel are defined. (2) According to the on-site electrical conditions, 32 east-west high-density resistivity imaging data acquisition and measurement lines are arranged in the study area for scanning and measurement, and the length of each test line is 378m, and the west of the line of measurement is in the village of Jiazhuang, and the east to the east of the eight-village-high-eight village in the town of Liuliu Town, and the total length is 12096m; and collecting 24 sounding points in the measuring line which can reflect the existence of the sand layer of the ancient river, and drawing the electric sounding curve to obtain the parameter information of the electrical property of the rock mass; and (3) carrying out data preprocessing, inversion calculation and drawing and the like of the collected field experimental data, A two-dimensional high-density resistivity image and an electric sounding curve are obtained, and the spatial structure characteristics of the rock mass are analyzed, such as the location of the ancient river channel, the depth of the burial, and the like. Through the above research, the following research results have been obtained: (1) The whole river channel in the study area is characterized by high resistance, and the resistivity value of the unconsolidated diagenetic area is in the range of 20-40惟 路 m, and the lithology is dominated by fine sand and fine sand, and in the local consolidation diagenetic area, The resistivity value can reach a few hundred ohms 路 m; the resistivity of the surrounding rock is represented by low resistance, and the resistivity value is in the range of 0-20 惟 路 m, and the lithology is dominated by the surface covering soil layer and the clay layer. (2) Based on the two-dimensional high-density resistivity image analysis, the paleochannel of this section is in the direction of WS-EN, the east and west is about 1400m, and the location of the east and west is clear; the depth of the sand layer in the middle of the channel is large, the buried depth of the two ends is small, and the large-鈥淯鈥，
本文编号：2391110
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