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2019年度环境地球科学学科项目评审与成果分析

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地球科学进展 2019年第11期34卷 1189-1201页

作者：刘羽王军李慧徐奴文张士秀周志祥王书兵蒲生彦吴国灿董紫君国家自然科学基金委员会地球科学部

着重分析了2019年度环境地球科学学科各类项目申请受理、评议和资助情况,并指出了申请和评议过程中暴露的问题;总结了2018年底该学科项目结题完成情况以及主要学科方向取得的研究进展。

关键词：环境地球科学项目评审资助成果

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水动力型滑坡形成运动机理与防控减灾技术

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工程地质学报 2019年第5期27卷 1131-1145页

作者：周家文陈明亮李海波徐奴文肖明砾杨兴国孙海龙戚顺超四川大学水利水电学院水力学与山区河流开发保护国家重点实验室

水动力型滑坡是指在冰川融雪、降雨、水位变动、地表径流及地下水活动等水动力因素驱动下而发生的斜坡岩土体失稳灾害。西南地区是水动力型滑坡尤其是库区滑坡的高发区,其失稳破坏直接威胁到人类的生命财产和基础设施的安全,且有可能造... 详细信息

水动力型滑坡是指在冰川融雪、降雨、水位变动、地表径流及地下水活动等水动力因素驱动下而发生的斜坡岩土体失稳灾害。西南地区是水动力型滑坡尤其是库区滑坡的高发区,其失稳破坏直接威胁到人类的生命财产和基础设施的安全,且有可能造成深远的次生灾害,提升水动力型滑坡灾害的监测预警、综合防控与应急处置水平极为迫切。水动力型滑坡易发于松散堆积层、破碎岩体、软岩以及含有软弱夹层的斜坡等地层,地质环境、水文活动以及人类活动干扰等因素的长期作用在水动力型滑坡的孕育过程中起着关键作用。斜坡在各种不利因素的持续交替作用下,逐渐产生变形破坏,稳定性不断降低并趋于极限失稳状态,最终在短期水文条件的改变下而导致整体失稳破坏。斜坡失稳后的滑坡动力过程非常复杂,尤其是特大型高位滑坡,在运动过程中可能会产生强烈的冲击破碎和沿程侵蚀铲刮现象,导致滑坡运动性态的改变和堆积方量的增大,水的存在会加剧滑坡沿程侵蚀铲刮作用以及导致运动性态向流态化转变而造成更远的运动距离和更广的致灾范围。水动力型滑坡是一个复杂的系统性问题,不同地质结构和水动力条件的滑坡变形破坏过程存在很大差异,远距离非接触式滑坡早期识别与监测技术以及基于人工智能和大数据且具备自主学习的滑坡预报预警方法是未来重要发展方向。水动力型滑坡防治涉及到工程建设、经济民生、社会等多方面因素,需要综合运用工程措施和非工程措施。在未来水利水电工程建设过程中,应重视库区滑坡的危害性,复建设施的修建应尽可能远离库区滑坡影响区。

关键词：水动力型滑坡形成机理破坏模式动力过程监测预警防控减灾

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基于MSFM的复杂速度岩体微震定位研究

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岩石力学与工程学报 2017年第2期36卷 394-406页

作者：郭亮戴峰徐奴文樊义林李彪四川大学水力学与山区河流开发保护国家重点实验室四川成都610065 中国长江三峡集团公司北京100038

快速精准的微震震源定位方法是微震监测技术更好地发挥岩体稳定性预测预警作用的基础。精确的初至波走时计算是提高微震定位精度的关键。针对实际工程中带有空洞和速度分区的复杂波速岩体,引入速度快、精度高和对复杂模型适应性强的多... 详细信息

快速精准的微震震源定位方法是微震监测技术更好地发挥岩体稳定性预测预警作用的基础。精确的初至波走时计算是提高微震定位精度的关键。针对实际工程中带有空洞和速度分区的复杂波速岩体,引入速度快、精度高和对复杂模型适应性强的多模板快速行进法multi-stencils fast marching methods(MSFM)用于初至波走时计算。该方法利用坐标旋转的方式生成新的计算模板,使网格对角邻点参与计算,提高了the Fast Marching Method(FMM)在对角方向的计算精度。首先,对比分析了一、二阶FMM和MSFM计算精度和效率,表明二阶MSFM具有更高的计算精度;其次,在分层速度岩体和带空洞岩体中分别采用单一速度模型和二阶MSFM计算初至波走时,通过与解析解对比发现,二阶MSFM较单一速度模型的计算绝对误差平均减小了97.65%和95.18%;然后,建立速度分层且带有隧洞的岩体模型,验证了二阶MSFM算法对复杂速度模型适应性极强的特点;最后,提出了基于MSFM的复杂速度岩体微震定位算法,并将其应用到白鹤滩水电站左岸边坡微震定位。通过对现场采集的4个爆破事件进行定位试算,得到使定位误差平均值最小(9.6 m)的相对最优层速度组合并用于考虑空洞的速度模型构建,爆破事件走时正演验证了本速度模型的可靠性。对2015年5月的128个微震事件分别采用单一速度模型和提出的定位算法进行定位,通过对比定位效果,发现后者定位的事件较前者在岩体主要损伤区(层内错动带LS331和LS337)附近有更明显呈条带状分布的聚集现象。研究表明MSFM算法作为走时正演方法具有很好的应用价值,提出的基于MSFM的微震定位方法能够有效地提高震源定位精度。

关键词：水利工程微震定位复杂速度走时计算 MSFM 白鹤滩水电站

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Microseismicity and its time-frequency characteristics of the left bank slope at the Jinping first-stage hydropower station during reservoir impoundment

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ENVIRONMENTAL EARTH SCIENCES 2016年第7期75卷 1-17页

作者： xu, nuwen Dai, Feng Zhou, Zhong Jiang, Peng Zhao, Tao Sichuan Univ State Key Lab Hydraul & Mt River Engn Coll Water Resource & Hydropower Chengdu 610065 Sichuan Peoples R China PowerChina Chengdu Engn Corp Ltd Chengdu 610072 Sichuan Peoples R China

The instability risk associated with the left bank slope of the Jinping first-stage hydropower station in south-western China may increase as a result of the initial impoundment of the reservoir and the raising and lowering of the reservoir level. To improve our understanding of the rock slope stability and the real-time behaviour of the composite system of rock slope and dam, an existing microseismic (MS) monitoring system installed on May 2009 was improved in early 2014. This investigation represents the first time such a technique has been used to evaluate the stability of a high rock slope in China. The safety and maintenance of the rock slope during the reservoir impoundment were investigated through the development of fast and accurate real-time event location technique aimed at assessing the evolution and migration of the seismic activity and through the development of capabilities for forecasting the rock slope stability. Numerous MS events in the rock slope have been recorded using the MS monitoring system. Zones of damaged rock mass were identified based on a spatio-temporal analysis of the seismic activity during the impoundment period. Moreover, a waveform decomposition method based on the S transform was proposed for processing the seismic waveforms during the construction and impoundment periods of the left bank slope, and the time-frequency characteristics of seismic events during these two periods were thus compared. The understanding of the relationships between the time-frequency parameters variations in the seismic signals and the rock mass damage can provide a basis for evaluating the stability of similar rock slopes.

关键词： Rock slope Jinping first-stage hydropower station Microseismic monitoring Time-frequency characteristics Impoundment

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乌东德水电站右岸地下厂房开挖围岩破坏模式及形成机制研究

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岩石力学与工程学报 2017年第4期36卷 781-793页

作者：李昂戴峰徐奴文顾功开刘科李彪四川大学建筑与环境学院成都四川610065 四川大学水力学与山区河流开发保护国家重点实验室成都四川610065 成都理工大学地质灾害防治与地质环境保护国家重点实验室成都四川610059 中国长江三峡集团公司北京100038

乌东德水电站右岸地下厂房洞室群布置复杂,中低应力条件下,"陡倾、小夹角"等不利岩层产状导致结构面控制型破坏现象突出。结合地质、现场勘查、常规监测、微震监测及数值模拟资料,全面总结和分析右岸厂房下游拱座岩体破坏模... 详细信息

乌东德水电站右岸地下厂房洞室群布置复杂,中低应力条件下,"陡倾、小夹角"等不利岩层产状导致结构面控制型破坏现象突出。结合地质、现场勘查、常规监测、微震监测及数值模拟资料,全面总结和分析右岸厂房下游拱座岩体破坏模式及形成机制。首先,基于现场勘查及常规监测资料,归纳和总结围岩破坏的基本特征与规律,包括其破坏形式、空间位置、破坏规模、破坏发展特征等主要信息;其次,总结岩体破坏孕育、发展过程中微震活动强度的时间演化规律,分析得到基于微震活动特征的层状岩体破坏前兆;最后,采用"微震监测"为主"数值模拟"为辅的综合分析手段,揭示下游拱座岩体发生弯曲倾倒的破坏本质及其形成机制,探讨岩体结构对拱座围岩破坏的力学影响机制。该研究可为陡倾层状岩体中大型地下洞室优化开挖方案和支护措施提供依据,也可为同类大型地下洞室相似围岩破坏的防控提供参考。

关键词：岩石力学地下厂房层状岩体微震监测数值模拟破坏机制

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Deformation forecasting and stability analysis of large-scale underground powerhouse caverns from microseismic monitoring

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INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES 2016年 86卷 269-281页

作者： Dai, Feng Li, Biao xu, nuwen Fan, Yilin Zhang, Chuanqing Sichuan Univ Coll Water Resource & Hydropower State Key Lab Hydraul & Mt River Engn Chengdu 610064 Sichuan Peoples R China China Three Gorges Corp Beijing Peoples R China Chinese Acad Sci Inst Rock & Soil Mech State Key Lab Geomech & Geotech Engn Wuhan Hubei Peoples R China

To assess the stability of the underground powerhouse caverns and analyse the failure mechanism of the surrounding rock mass at the Baihetan hydropower station in southwest China, a high-resolution microseismic (MS) monitoring system was implemented in the left-bank underground powerhouse caverns. Based on the temporal and spatial distribution of MS events, the correlation between MS activities and construction was established, and three damage regions for the surrounding rock mass during excavation were identified. MS clusters were found to occur most often in stress-concentration regions of the underground powerhouse caverns and to result from various factors, including excavation-induced unloading and geological structure activation. The seismic source parameters (i.e., moment magnitudes and (S-wave) to (P-wave) energy ratios, E-s/E-p) of the three MS clusters demonstrate the different failure modes and risks of the surrounding rock mass. The temporospatial evolution of the MS activities, apparent stress, and cumulative apparent volume in localized rock mass during the period of a typical large deformation were used to develop a comprehensive analytical method for forecasting the deformation of the surrounding rock mass. Thus, this comprehensive analytical method, which incorporates MS monitoring, conventional monitoring, geological survey and construction, is promising for identifying the damage zones and forecasting the macro-deformation of the surrounding rock mass in underground powerhouse caverns subjected to excavation. (C) 2016 Elsevier Ltd. All rights reserved.

关键词： Underground powerhouse caverns Microseismic monitoring Excavation Stability analysis Deformation forecasting

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Stability analysis of bedding rock slopes during excavation based on microseismic monitoring

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Yanshilixue Yu Gongcheng xuebao/Chinese Journal of Rock Mechanics and Engineering 2016年第10期35卷 2089-2097页

作者： xu, nuwen Li, Biao Dai, Feng Fan, Yilin xu, Jian School of Civil Engineering Shandong University JinanShandong250100 China State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan University ChengduSichuan610065 China China Three Gorges Corporation Beijing100038 China

A high-precision microseismic(MS) monitoring system was installed to evaluate the stability of the left bank bedding slope at Baihetan during excavation. The main damage regions of the left bank slope were delineated through real-time monitoring and analyzing of the MS activities. The initiation, propagation, extension and coalescence mechanisms of mircocracks were revealed using the realistic failure process analysis(RFPA) approach. The full progressive failure processes of the rock slope at atypical section were reproduced. The MS activities were found to match well with the excavation disturbances. The MS events induced by the slope excavation were mainly distributed around the dam spandrel, especially along the internal staggered zones LS331, LS337 and the hanging wall of fault F17(610-700 m), forming the main damage regions of the slope. Influenced by the excavation-induced unloading of the slope, the stress concentration was highlighted in the weak structures such as LS331, LS337 and F17, and myriads of rock failure elements continuously propagated in these regions, resulting in the rock failure along the weak structures. Numerical simulation results coincided with the trend of spatial macro evolution of MS activities. © 2016, Science Press. All right reserved.

关键词： Excavation

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白鹤滩水电站岩质边坡微震活动特征研究

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防灾减灾工程学报 2017年第5期37卷 769-775页

作者：胡中华徐奴文戴峰李昂张敏蒋雄四川大学水力学与山区河流开发保护国家重点实验室四川成都610065

白鹤滩水电站左岸边坡高陡,应力条件复杂,存在LS_(331)、LS_(337)、LS_(3319)层内错动带,F17断层等软弱结构面,施工期和运营期安全问题十分突出。为评价其左岸边坡开挖稳定性,利用微震监测系统对边坡微震活动进行实时监测,并分析微震活... 详细信息

白鹤滩水电站左岸边坡高陡,应力条件复杂,存在LS_(331)、LS_(337)、LS_(3319)层内错动带,F17断层等软弱结构面,施工期和运营期安全问题十分突出。为评价其左岸边坡开挖稳定性,利用微震监测系统对边坡微震活动进行实时监测,并分析微震活动的时空以及震级分布,揭示岩质边坡开挖扰动下的微震活动特性及其施工响应特征。结果表明:开挖强度越大,边坡损伤越大,微震活动越活跃;爆破后0.5h内应力急剧调整,微震活动频繁;震级分布在-1.6~0.4之间,爆破开挖诱发大量震级小能量低的微震事件,诱发边坡的渐进损伤;软弱结构面是微震事件的主要活动区域,具有发生破坏变形的可能性;左岸边坡岩石破裂以复合型破坏和剪切破坏为主,伴随少量拉伸破坏。该研究可为工程后续开挖和支护提供参考,为同类微震活动特性分析提供一定的借鉴。

关键词：白鹤滩水电站岩质边坡微震监测爆破开挖软弱结构面

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Integrated Analysis of the Formation Mechanism of Cracks in a Concrete Dam Using Microseismic Monitoring and Numerical Simulation

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JOURNAL OF SENSORS 2016年第8-4期2016卷 5720565-5720565页

作者： He, Gang Li, Biao Wang, xuben xu, nuwen Chengdu Univ Technol Minist Educ Key Lab Earth Explorat & Informat Tech Chengdu 610059 Peoples R China Sichuan Hydropower Engn Invest Co Ltd Chengdu 610072 Peoples R China Sichuan Univ State Key Lab Hydraul & Mt River Engn Coll Water Resource & Hydropower Chengdu 610065 Peoples R China

The dam of Guanyinyan hydropower station is composed of a concrete gravity dam in the left bank and a rockfill dam in the right bank. During the operation of the hydropower station, several surface cracks occurred in the concrete gravity dam, which threatened the stability of the dam. To evaluate the evolution trend of the cracks and forecast the potential risk of the dam, the microseismic (MS) monitoring technique and finite-element method were used. First, the concrete three-point bending field test was performed to prove the reliability of the MS technique in monitoring the concrete cracks. The MS monitoring results were consistent with the simulation results. Then, the MS monitoring system was installed in the dam body. By analysing the MS activities before and after the impoundment, the evolution trend of the cracks and potential risk of the dam were evaluated and forecasted. The simulation results were also consistent with the monitoring results. These results can provide significant references for the operation safety of the dam and also present a new thought for the risk evaluation of similar dam engineering.

关键词： Gravity dams Earth dams Water power Seismology Crack formation in solids Computer simulation

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Microseismic characteristic analysis of underground powerhouse at Baihetan hydropower station subjected to excavation

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Yanshilixue Yu Gongcheng xuebao/Chinese Journal of Rock Mechanics and Engineering 2016年第4期35卷 692-703页

作者： Dai, Feng Li, Biao xu, nuwen Fan, Yilin xu, Jian Liu, Jun State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan University ChengduSichuan610065 China China Three Gorges Corporation Beijing100038 China Sinohydro Bureau 7 Co. Ltd. ChengduSichuan610081 China

Because of the large size of the underground powerhouse of Baihetan hydropower station at left bank, the local failures of surrounding rock occurred frequently subjected to excavation. To study the mechanisms of rock deformation and failure subjected to unloading caused by excavation, an ESG(Engineering Seismology Group) monitoring system was applied to monitor the microfractures in real time during the excavation processes in the underground powerhouse. Microseismic(MS) activity was found to be in good agreement with the excavation. Three potential failure zones of the underground powerhouse under the first layer excavation were revealed, i.e., the downstream spandrel between unit 4 and unit 5 of the main powerhouse, the upstream spandrel between unit 6 and unit 7 of the main powerhouse, and the crown above unit 8 of the main powerhouse to the crown of the transformer chamber. The moment magnitudes and Es/Ep of microseismic clusters controlled by the excavation strength and faults were very different, resulting in the different potential failure modes of surrounding rock. The targeted supports should be adopted in the MS clusters based on the evolutional MS characteristics. Several days before the local deformation of the surrounding rock, the area manifested with the accelerated cluster of MS events, quick increase of the apparent stress, but rare change of the cumulative apparent volume. © 2016, Science Press. All right reserved.

关键词： Excavation

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