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现代地质 ›› 2023, Vol. 37 ›› Issue (01): 31-39.DOI: 10.19657/j.geoscience.1000-8527.2022.070

• 地球物理与信息技术 • 上一篇    下一篇

高密度电法电性结构揭示天山天池堆积坝体厚度及其阻渗稳水功能分析

尚彦军1,2(), 金维浚1(), 伊学涛1,2, 姜东廷3, HASAN Muhammad1   

  1. 1.中国科学院地质与地球物理研究所页岩气与地质工程重点实验室, 北京 100029
    2.中国科学院大学地球与行星科学学院, 北京 100049
    3.新疆地质灾害防治重点实验室 (新疆工程学院),新疆 乌鲁木齐 830023
  • 收稿日期:2021-06-02 修回日期:2022-09-30 出版日期:2023-02-10 发布日期:2023-03-20
  • 通讯作者: 金维浚,男,博士,副研究员,1963年出生,勘探地球物理专业,主要从事工程物探研究。Email: wjjin@mail.iggcas.ac.cn。
  • 作者简介:尚彦军,男,博士,研究员,博士生导师,1967年出生,水文地质工程地质专业,主要从事岩体结构力学研究。Email: jun94@mail.iggcas.ac.cn
  • 基金资助:
    科技部“第二次青藏高原综合科学考察研究”项目(2019QZKK0904);国家自然科学基金项目(41772320);地质灾害防治与地质环境保护国家重点实验室课题(SKLGP2017K021)

Dam Structure and Hydrogeological Conditions of Tianchi Lake in Tianshan Mountains: Perspectives from Electrical Resistivity Tomography and Accumulation Deposit Structure

SHANG Yanjun1,2(), JIN Weijun1(), YI Xuetao1,2, JIANG Dongting3, HASAN Muhammad1   

  1. 1. Key Laboratory of Shale Gas and Geoengineering, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China
    2. College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
    3. Xinjiang Key Laboratory of Geohazard Prevention (Xinjiang Institute of Engineering), Urumqi, Xinjiang 830023, China
  • Received:2021-06-02 Revised:2022-09-30 Online:2023-02-10 Published:2023-03-20

摘要:

天山天池北堆积坝体结构受其成因和演化控制,影响其含水和渗流特性。对该坝体稳定至关重要的下伏基岩埋深、坝体结构阻渗水结构特征等需现场探测并给出科学判断。在地质调查基础上采用高密度电法对天池堆积坝体结构进行探测,首次获得深达下伏基岩的堆积坝体纵向和横向电性剖面。结合光释光测年、水化学成分对比、水量平衡计算等手段,分析坝体堆积物形成时代以及坝体水文地质结构特征。结果显示:天池坝堆积体厚度大于100 m并可分为3层,上部浅表层滑坡形成的巨大块石层厚30~40 m且基本不含水,其下松散含水层厚度为30~50 m;下部为较低电阻率弱透水的冰碛物,主要分布在坝体下游和东端;底部为高电阻率不透水的石炭系火山岩。坝体中间部位地下水集中下渗补给了西小天池。同时靠坝体东侧发育排泄通道,呈现多处溢水点,控制了飞龙涧左岸下降泉季节性发育,同河谷冲刷作用一起影响并导致下游左岸冰碛物中发育4处滑坡体。电法剖面揭示出与坝体轴向近平行的2条隐伏断层,其中堆积坝高堤处气象台所在山丘上游一侧发育一条近东西走向并倾向上游的断层F1,构成地下水阻隔带而使天池堆积坝上游潜水水位呈现一定雍高,同坝体下伏基岩和弱透水冰碛物联合组成的坝体结构致使旱季天池水不会大量溢出,夏季丰水时浅表泉水渗漏,保证了天池水满而不溢、结构松而不垮。由此构建该堆积体内断层和地层结构组成的浅表导水模型,计算得出天池堆积体地下水排泄量约为1200 m3/d,天池总下泄水量为52×104~113×104 m3 /d(从冬季到夏季),维持了天池湖水动态稳定。

关键词: 天池, 坝体结构, 高密度电法, 电性结构, 阻渗水功能

Abstract:

The accumulation dam structure at the northern exit of Tianchi Lake in Tianshan Mountains is controlled by its origin and evolution, which affects its groundwater hosting and seepage characteristics. The bedrock burial depth and water diversion structure are crucial to the dam stability, which remains unresolved for many years. Based on geological survey, we used electrical resistivity tomography, optical luminescence dating and hydrochemical analysis to detect the structure of Tianchi Lake accumulation dam, and to determine the age of material formation and the hydrogeological features of the dam. The results show that the Tianchi accumulates are over 100 meter-thick, and the upper shallow massive boulder layer and lower aquifer is 30-40 meter and 30-50 meter thick, respectively, which was underlain by igneous rock complex. Groundwater in the middle part of the dam infiltrates intensively and replenishes the western Xiaotianchi Lake. There are many overflow points and discharge channels on the left bank of the Feilong Stream in the east, which control the seasonal occurrence of shallow spring there. An EW-striking fault (inclining to the upstream) is present beneath the hill of the meteorological station, which forms an aquitard in the Tianchi Lake and rises the phreatic water level. The major water diversion structure model (composed of fault and stratigraphic structure) in the accumulation body is preliminarily constructed. We calculated that the groundwater discharge of the Tianchi dam is 1200 m3/d, whilst the total water discharge is 52×104-113×104 m3/d (from winter to summer).

Key words: Tianchi Lake, accumulation dam structure, electrical resistivity tomography, electrical structure, impervious function

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