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基于矿物溶解理论的砂岩化学损伤动态模型

材料导报 2024年第8期38卷 159-165页

作者：梁艳玲霍润科宋战平穆彦虎秋添宋子羿西安建筑科技大学土木工程学院西安710055 西安建筑科技大学陕西省岩土与地下空间工程重点实验室西安710055 中国科学院西北生态环境资源研究院冻土工程国家重点实验室兰州730050

酸腐蚀环境下岩石物理力学性质的劣化本质上由岩石矿物的溶解引发的孔隙微裂隙的扩展贯通所致。为研究酸性环境下砂岩矿物的溶解特性,选择pH=1、3的盐酸溶液为腐蚀环境,借助X射线衍射试验鉴定砂岩矿物成分及含量,测试不同浸泡周期下溶液... 详细信息

酸腐蚀环境下岩石物理力学性质的劣化本质上由岩石矿物的溶解引发的孔隙微裂隙的扩展贯通所致。为研究酸性环境下砂岩矿物的溶解特性,选择pH=1、3的盐酸溶液为腐蚀环境,借助X射线衍射试验鉴定砂岩矿物成分及含量,测试不同浸泡周期下溶液的pH值、阳离子浓度、岩样的质量及其纵波波速,并通过矿物溶解理论与化学动力学原理,建立反映整个腐蚀过程的砂岩化学损伤动态模型。研究结果表明:酸性环境下砂岩的损伤主要由长石和方解石的溶解所致,矿物溶解反应分为界面吸附、界面交换、解吸附三个步骤,且步骤最慢者对整个反应起控制作用。矿物溶解速率与H+浓度的n次幂成正比,且0

关键词：砂岩矿物溶解化学损伤模型孔隙度纵波波速

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寒区特长隧道斜井对隧道内温度影响实测研究

铁道工程学报 2024年第1期41卷 67-75页

作者：刘杰朱小明李晓民张坤樊江曹贵穆彦虎郑波甘肃省公路交通建设集团有限公司兰州730000 甘肃省交通规划勘察设计院股份有限公司兰州730030 西北民族大学兰州730124 中国科学院西北生态环境资源研究院兰州730030 中铁西南科学研究院有限公司成都611731

研究目的:寒区隧道内温度分布是保温设计和冻害防治的关键和前提,其影响因素可归纳为三类,即环境气象、工程结构以及交通因素。相较于环境气象和交通因素,目前针对工程因素,尤其特长隧道通风设施对隧道内温度分布影响的研究不足。结合... 详细信息

研究目的:寒区隧道内温度分布是保温设计和冻害防治的关键和前提,其影响因素可归纳为三类,即环境气象、工程结构以及交通因素。相较于环境气象和交通因素,目前针对工程因素,尤其特长隧道通风设施对隧道内温度分布影响的研究不足。结合青藏高原东南缘某高速公路特长隧道,系统开展了隧址区环境气象与不同建设阶段隧道内气温的空间分布与季节变化的连续观测,重点论述了通风斜井对隧道内温度环境的影响。研究结论:(1)隧道贯通前,洞内通风差,环境气温对隧道内温度的影响进深为300~400 m,隧道洞口段气温年平均值和振幅随进深增加呈指数形式增加和减小;(2)隧道开挖至斜井并与其连通后,在烟囱效应作用下,冷季时自进口至斜井形成稳定的单向风,洞内气温基本呈线性分布,梯度约为0.5℃/100 m;(3)隧道贯通后,冷季时斜井烟囱效应引发隧道内形成稳定的自进口、出口至斜井的双向通风,洞内温度呈现基本以斜井为中心的对称分布,全隧道范围内出现显著负温;(4)通风斜井对隧道内温度分布规律及负温段长度均有显著的影响,在寒区隧道保温设防和冻害防治中应予以考虑。

关键词：寒区隧道通风斜井温度分布烟囱效应现场监测

考虑日变化过程的寒区隧道温度场解析解与现场监测研究

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铁道科学与工程学报 2024年第6期21卷 2406-2416页

作者：张力杰穆彦虎田毅王玉林朱小明张坤郑波李凌洁中国科学院西北生态环境资源研究院冻土工程国家重点实验室甘肃兰州730000 中国科学院大学北京100049 甘肃省公路交通建设集团有限公司甘肃兰州730000 甘肃省交通规划勘察设计院股份有限公司甘肃兰州730030 西北民族大学土木工程学院甘肃兰州730124 中铁西南科学研究院有限公司四川成都611731

负温环境是隧道冻害发生的必要条件,因此隧道内气温、衬砌和围岩体温度的空间分布与时间变化过程是寒区隧道冻害机理和防治研究的关键。目前,已有研究多采用月平均值来描述隧道内的温度环境及其影响因素,忽略了其日变化过程,可能低估隧... 详细信息

负温环境是隧道冻害发生的必要条件,因此隧道内气温、衬砌和围岩体温度的空间分布与时间变化过程是寒区隧道冻害机理和防治研究的关键。目前,已有研究多采用月平均值来描述隧道内的温度环境及其影响因素,忽略了其日变化过程,可能低估隧道内负温段长度和冻结深度以及衬砌结构经历的冻融作用,由此造成保温设防设计的不足。以青藏高原东北缘的一高海拔寒区公路特长隧道为例,通过对洞内气温的自动连续观测,统计分析了隧道内气温的日变化特征。运用叠加原理将寒区隧道径向温度场分为稳态和瞬态,在求解瞬态温度场过程中采用Laplace变换,同时考虑隧道内气温的日变化和年变化过程,构建了包括保温层、衬砌和围岩体等多层介质的寒区隧道径向温度场解析解,对比分析了考虑与不考虑气温日变化过程隧道衬砌结构温度的变化规律。结果表明,隧道内气温的日变化幅度在进、出口段较为显著,日振幅可达11℃以上,随着进深增加逐渐减小,至隧道中部气温日振幅降至2℃以内。同时,隧道内气温日振幅表现出明显的季节性,冷季明显大于暖季。考虑气温的日变化过程的解析解能够更准确地反映隧道结构所经历的冻结时长和冻融循环次数,与隧道结构层内实测温度的波动范围更加接近。现场监测结果和理论解析方法对于寒区隧道衬砌混凝土抗冻等级选择和冻融损伤预测以及衬砌挂冰和路面结冰预警等具有积极意义。

关键词：寒区隧道温度场日变化现场监测解析解

Thermal Characteristics of the Embankment with Crushed Rock Side Slope to Mitigate Thaw Settlement Hazards of the Qinghai-Tibet Railway

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Acta Geologica Sinica(English Edition) 2009年第5期83卷 1000-1007页

作者： LI Guoyu mu yanhu ZHANG Xia State Key Laboratory of Frozen Soil Engineering CAREERL Chinese Academy of Science Lanzhou 730000 China School of Energy and Power Engineering Lanzhou University of Technology Lanzhou 730050 China

Permafrost （perennially frozen ground） appears widely in the Golmud-Lhasa section of the Qinghai-Tibet railway and is characterized by high ground temperature （≥1℃） and massive ground ice. Under the scenarios of global warming and human activity, the permafrost under the railway will gradually thaw and the massive ground ice will slowly melt, resulting in some thaw settlement hazards, which mainly include longitudinal and lateral cracks, and slope failure. The crushed rock layer has a thermal semiconductor effect under the periodic fluctuation of natural air. It can be used to lower the temperature of the underlying permafrost along the Qinghai-Tibet railway, and mitigate the thaw settlement hazards of the subgrade. In the present paper, the daily and annual changes in the thermal characteristics of the embankment with crushed rock side slope （ECRSS） were quantitatively simulated using the numerical method to study the cooling effect of the crushed rock layer and its mitigative ability. The results showed that the ECRSS absorbed some heat in the daytime in summer, but part of it was released at night, which accounted for approximately 20% of that absorbed. Within a year, it removed more heat from the railway subgrade in winter than that absorbed in summer. It can store approximately 20% of the ＂cold＂ energy in subgrade. Therefore, ECRSS is a better measure to mitigate thaw settlement hazards to the railway.

关键词： Qinghai-Tibet railway climate change embankment with crushed rock side slope,numerical analysis thaw settlement

Field Observations of Near-Surface Wind Flow Across Expressway Embankment on the Qinghai–Tibet Plateau

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Engineering 2022年第7期8卷 169-180页

作者： yanhu mu Wei Ma Zhaohui(Joey)Yang Xiaolin Li Kun Zhang Yuncheng Mao State Key Laboratory of Frozen Ground Engineering Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China College of Engineering University of Alaska AnchorageAnchorageAK 99508USA College of Civil Engineering and Architecture Jiaxing UniversityJiaxing 314001China School of Civil Engineering Northwest Minzu UniversityLanzhou 730024China

Crushed rock layers(CRLs),ventilation ducts(VDs)and thermosyphons are air-cooling structures(ACSs)widely used for maintaining the long-term stability of engineered infrastructures in permafrost *** ACSs can effectively cool and maintain the permafrost subgrade’s frozen state under climate warming by facilitating heat exchange with ambient air in cold *** convection is a crucial working mechanism of these ACSs,it is imperative to understand the near-surface wind flow(NSWF)across a constructed infrastructure,such as an *** article describes a yearlong field observation of the NSWF across an experimental expressway embankment,the first of its kind on the Qinghai–Tibet Plateau(QTP).The wind speed and direction along a transect perpendicular to the embankment on both the windward and leeward sides and at four different heights above the ground surface were collected and *** results showed that the embankment has a considerable impact on the NSWF speed within a distance of up to ten times its height,and in the direction on the leeward side.A power law can well describe the speed profiles of NSWF across the embankment,with the power-law indices(PLIs)varying from 0.14 to *** an annual basis,the fitted NSWF PLI far away from the embankment was 0.19,which differs substantially from the values widely used in previous thermal performance evaluations of ACSs on the ***,the significance of the NSWF to the thermal performance of the ACSs,particularly the CRLs and VDs,in linear transportation infrastructure is *** is concluded that underestimating the PLI and neglecting wind direction variations may lead to unconservative designs of the *** results reported in this study can provide valuable guidance for infrastructure engineering on the QTP and other similar permafrost regions.

关键词： Near-surface wind flow Field observation Air-cooling structures Linear transportation infrastructure Qinghai–Tibet Plateau

Dynamic behavior of the Qinghai-Tibetan railway embankment in permafrost regions under trained-induced vertical loads

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Research in Cold and Arid Regions 2020年第4期12卷 189-199页

作者： Tuo Chen ZhiJian Wu yanhu mu Wei Ma JianZhou Wang State Key Laboratory for Geomechanics and Deep Underground Engineering China University of Mining and TechnologyXuzhouJiangsu 221116China State Key Laboratory of Frozen Soil Engineering Northwest Institute of Eco-environment and ResourcesChinese Academy of SciencesLanzhouGansu 730000China School of Transportation Engineering Nanjing Tech UniversityNanjingJiangsu 210009China

The unfrozen water content and ice content of frozen soil change continuously with varying temperatures,resulting in the temperature dependence of mechanical properties of frozen *** the dynamic behavior of embankment in permafrost regions under train loading also alters with *** on a series of strong-motion tests that were carried out on the traditional embankment of Qinghai-Tibet Railway(QTR)in permafrost regions,the acceleration waveforms recorded at the embankment shoulder and slope toes were *** results show an obvious attenuation effect on the vertical train loading from road shoulder to slope ***,numerical simulations of a traditional embankment under vertical train loading in different seasons were conducted,and the dynamic behavior of the embankment was *** results show that the vibration attenuation in the cold season is greater than that in the warm *** maximum acceleration of vibration drops to about 5%when the train vibration load is transferred through the embankment into the permafrost,and the high-frequency components are absorbed when the vibration transmits ***,the dynamic stress under the dynamic train loading decreases exponentially with an increasing depth in different *** results can be a reference for design and maintenance of embankments in permafrost regions.

关键词： permafrost railway embankment numerical analysis dynamic response

Seepage influence of supra-permafrost groundwater on thermal field of embankment on Qinghai-Tibet Plateau,China

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寒旱区科学:英文版 2023年第3期15卷 132-140页

作者： MingTang Chai Yuan Luo Yu Gao Wei Ma yanhu mu School of Civil Engineering and Hydraulic Engineering Ningxia UniversityYinchuanNingxia 750021China State Key Laboratory of Frozen Soil Engineering Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhouGansu 730000China University of Chinese Academy of Sciences Beijing 100049China

As a unique hydro-geological phenomenon in permafrost regions,the seepage of supra-permafrost groundwater will carry a large amount of heat and cause differential settlement in the *** paper presents the results of a field study monitoring the supra-permafrost groundwater levels on both sides of an embankment in permafrost *** describes a two-dimensional coupled hydro-thermal model and uses it to analyze the influence of seepage on its temperature field considering climate *** results show that seepage exacerbates permafrost thawing and thickens the active *** thermal influence on the sunny side of the embankment toe is more significant than that on the shady side,which will cause differential settlement in the *** 50 years of operation,the embankment soil temperature with seepage during freezing is 0.2C warmer than that without seepage,and the thermal influence diminished with the increase in ***,seepage influences the thermal regime in vertical and horizontal directions of the *** freezing seasons,the thaw depth increases,and the horizontal thaw range *** thawing seasons,the thaw range grows both vertically and horizontally.

关键词： Permafrost Embankment Hydro-thermal coupling Thawed inter-layer

Relationship between ponding and topographic factors along the China-Russia Crude Oil Pipeline in permafrost regions

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Research in Cold and Arid Regions 2019年第6期11卷 419-427页

作者： MingTang Chai yanhu mu GuoYu Li Wei Ma Fei Wang State Key Laboratory of Frozen Soil Engineering Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhouGansu 730000China University of Chinese Academy of Sciences Beijing 100049China

The original landform along the China Russia Crude Oil Pipeline(CRCOP,line 2)was disturbed during installation of pavement for the *** and vegetation coverage is dense,and runoff develops along the *** the opera tion of the CRCOP(line 2)began in 2018,ponding has appeared on both sides of the *** there is no drainage,ponding can hardly dissipate,due to the low permeability of the permafrost *** the supply of surface flow and the transportation of oil at positive temperatures,ponding promotes an increase in temperature and changes the boundary ther mal conditions of the ***,when the ponding freezes and thaws,frost heave threatens operational safety of the ***,the ponding can affect the thermal condition of line *** this paper,the distribution of pond ing along the CRCOP was obtained by field *** type and cause of ponding were summarized,and the catch ment and stream order were extracted by the Digital Elevation Model(DEM).According to the statistical results in attri butes for topographic factors,it is known that ponding along the pipeline is relative to elevation,slope,aspect,and the Topographic Wetness Index(TWI).Water easily accumulates at altitudes of 300450 m,slopes within 3°5°,aspect in the northeast or south,TWI within 1316,flow direction in north east south,and flow length within 90150 *** paper proposes a theoretical basis for the cause and characteristics of ponding along the pipeline.

关键词： permafrost Digital Elevation Model(DEM) Topographic Wetness Index(TWI) pipeline ponding

Purification of heavy metal chromium in saturated sand by artificial freezing:Mechanism and method optimization

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Research in Cold and Arid Regions 2022年第6期14卷 370-376页

作者： JianZhou Wang HaiHang Wang Sen Yang GuoQing Zhou yanhu mu State Key Laboratory for Geomechanics and Deep Underground Engineering China University of Mining and TechnologyXuzhouJiangsu 221116China School of Mechanics and Civil Engineering China University of Mining and TechnologyXuzhouJiangsu 221116China Shaoxing Construction Quality and Safety Supervision Terminal ShaoxingZhejiang 312000China State Key Laboratory of Frozen Soil Engineering Northwest Institute of Eco-Environment and ResourcesCASLanzhouGansu 730000China

Heavy metal pollution of soil has become one of the most common hazards in human *** artificial freezing method,especially the progressive freezing method,can reduce heavy metal pollutants in the soil and promises to be an effective in-situ treatment of contaminated *** study analyzes the freezing purification mechanism of heavy metal contaminants in saturated sand and identifies three main factors that impact the effects of purification:freezing rate,initial concentration,and diffusion ***,one-dimensional freezing tests are carried out by different freezing *** experimental results show that the heavy metal chromium could only be removed effectively with a slow freezing *** optimizing the freezing mode and freezing rate,a long section of soil was frozen and purified,with the maximum purification rate reaching 65.8%.This study shows that it is feasible to treat contaminated saturated sand by a gradual-cooling freezing method.

关键词： Artificial freezing method Freezing purification mechanism Gradual cooling mode Heavy metal chromium