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Sheet Bulk Forming of Thin-Walled Components with External Gearing through Upsetting Using Controllable Deformation Zone Method 被引量:1
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作者 Xincun Zhuang Meile Liang +2 位作者 Shengfa Zhu Yin Zhu Zhen Zhao 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2021年第5期282-295,共14页
Sheet-bulk metal forming(SBMF)is a promising process for manufacturing complex sheet components with functional elements.In this study,the entire forming process for a typical thin-walled component with external geari... Sheet-bulk metal forming(SBMF)is a promising process for manufacturing complex sheet components with functional elements.In this study,the entire forming process for a typical thin-walled component with external gearing is investigated,including sheet forming and bulk forming processes.Deep drawn cups are prepared during sheet forming;subsequently,upsetting is performed on the sidewall to form external gearing.The upsetting method performed is known as upsetting with a controllable deformation zone(U-CDZ).Compared with the conventional upsetting method,a floating counter punch with a counter force is used in the U-CDZ method such that the forming mechanism is changed into the accumulation of the deformation zone instead of deformation throughout the entire sidewall.The effects of the counter force and material flow are investigated to understand the mechanism.The forming quality,i.e.,the formfilling and effective strain distribution,improved,whereas a high forming load is avoided.In addition,a punch with a lock bead is used to prevent folding at the inner corner during the experiment. 展开更多
关键词 Sheet-bulk metal forming Thin-walled components External gearing Controllable deformation zone
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Structures of Syn-deformational Granites in the Longquanguan Shear Zone and Their Monazite Electronic Microprobe Dating 被引量:10
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作者 ZHANG Jinjiang ZHAO Lan LIU Shuwen 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2006年第6期864-874,共11页
The Longquanguan shear zone is an important structural belt in the North China Craton, separating the underlying Fuping complex from the overlying Wutai complex. This shear zone has experienced three episodes of defor... The Longquanguan shear zone is an important structural belt in the North China Craton, separating the underlying Fuping complex from the overlying Wutai complex. This shear zone has experienced three episodes of deformation: the first and main episode is a ductile top-to-ESE shear along the gently northwest-west dipping foliations, while the other two episodes are later collapse sliding. Prolonged granites parallel to the shear foliations make one of the main compositions of the Longquanguan shear zone. These granites experienced deformation to form mylonitic rocks when they emplaced during the first episode of deformation. Structural characters of the granites and their contacts to the country rocks indicate that these granites possibly resulted from in-situ partial remelting by shearing, i.e., they are syn-deformational granites. Monazites in these mylonitic granites are magmatic minerals and their crystallization ages may represent ages of the magmatic events, and also the ages for the main deformation of the Longquanguan shear zone. Monazite electronic microprobe dating were carried on two samples of granite, which gives multiple peak ages, among which 1,846 Ma and 1,877 Ma are the main peak ages for the two samples. These ages represent the main deformation of the Longquanguan shear zone, which is consistent with the main regional geological event at about 1,850 Ma caused by the collision between the Eastern and Western Blocks in North China. The good match between the monazite ages and the corresponding regional tectono-thermal events shows the feasibility and reliability of monazite electronic microprobe dating. 展开更多
关键词 Longquanguan shear zone syn-deformational granite monazite electronic microprobe dating
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The Surface Rupture Zone and Coseismic Deformation Produced by the Yutian Ms7.3 Earthquake of 21 March 2008,Xinjiang 被引量:2
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作者 SHAN Xinjian QU Chunyan +5 位作者 WANG Chisheng ZHANG Guifang ZHANG Guohong SONG Xiaogang GUO Liming LIU Yunhua 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2012年第1期256-265,共10页
On 21 March 2008, a Ms7.3 earthquake occurred at Quickbird, Yutian County, Xinjiang. We attempt to reveal the features of the causative fault of this shock and its coseismic deformation field. Our work is based on ana... On 21 March 2008, a Ms7.3 earthquake occurred at Quickbird, Yutian County, Xinjiang. We attempt to reveal the features of the causative fault of this shock and its coseismic deformation field. Our work is based on analysis and interpretation to high-resolution satellite images as well as differential interferometric synthetic aperture radar (D-InSAR) data from the satellite Envisat SAR, coupled with seismicity, focal mechanism solutions and active tectonics in this region. The result shows that the 40 km-long, nearly NS trending surface rupture zone by this event lies on a range-front alluvial platform in Qira County. It is characterized by distinct linear traces and simple structure with 1-3-m-wide individual seams and maximum 6.5 m width of a collapse fracture. Along the rupture zone many secondary fractures and fault-bounded blocks are seen, exhibiting remarkable extension. The eoseismic deformation affected a large area 100~100 km2. D-InSAR analysis indicates that the interferometric deformation field is dominated by extensional faulting with a small strike-slip component. Along the causative fault, the western wall fell down and the eastern wall, that is the active unit, rose up, both with westerly vergence. Because of the big deformation gradients near the seismogenic fault, no interference fringes are seen on images, and what can be determined is a vertical displacement 70 cm or more between the two fault walls. According to the epicenter and differential occurrence times from the National Earthquake Information Center, China Earthquake Network Center, Harvard and USGS, it is suggested that the seismic fault ruptured from north to south. 展开更多
关键词 Yuntian Earthquake high resolution image D-INSAR surface rupture zone coseismic deformation field
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The Ductile Deformation Characteristics of Caledonian Intracontinental Orogeny in the Northeastern Jiangshan-Shaoxing Tectonic Zone:Insights from Magnetic Fabric Study and Its Geodynamic Implication 被引量:3
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作者 GONG Genhui CHEN Hanlin +2 位作者 WANG Fang LIN Xiubin MENG Lifeng 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2016年第1期75-87,共13页
The Jiangshan-Shaoxing tectonic zone was the northeastern boundary between the Yangtze Block and the Cathaysia Block during the Neoproterozoic and was an intracontinental orogenic belt during late of the early Paleozo... The Jiangshan-Shaoxing tectonic zone was the northeastern boundary between the Yangtze Block and the Cathaysia Block during the Neoproterozoic and was an intracontinental orogenic belt during late of the early Paleozoic. In this tectonic zone, there develops a lot of mylonite underwent strong ductile deformation and schist, gneiss, and amphibolite with medium and high grade metamorphism which was formed during the late of early Paleozoic. The research of geometry and kinematic of ductile deformation in Jiangshan-Shaoxing tectonic zone is very important to reveal the tectonic process of intracontinental orogeny. This paper uses the anisotropy of magnetic susceptibility (AMS) to determine the ductile deformation geometry and kinematic of Jiangshan-Shaoxing tectonic zone combing with the field survey. In this study, 190 specimens of 19 locations and 221 specimens of 23 locations from Wangjiazhai section and Lipu-Sizhai section were analyzed. The magnetic foliation over magnetic lineation in both Wangjiazhai and Lipu-Sizhai sections together with the field observations indicated a compressional deformation pattern. 3 and 4 strong ductile deformation zones can be established in the Wangjiazhai section and the Lipu-Sizhai section, respectively. According to the magnetic fabric and petro-fabric studies, the Northeastern Jiangshan-Shaoxing tectonic zone suffered two kinds of deformation patterns during the late early Paleozoic, i.e., the thrusting deformation followed by sinistral shear deformation. 展开更多
关键词 magnetic fabric ductile deformation deformation intensity deformation pattern Jiangshan-Shaoxing tectonic zone
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Structural and Geochronological Evidence for Multiple Episodes of Tertiary Deformation along the Ailaoshan-Red River Shear Zone, Southeastern Asia, Since the Paleocene 被引量:28
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作者 ZHANG Jinjiang ZHONG Dalai +1 位作者 SANG Haiqing ZHOU Yong 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2006年第1期79-96,共18页
Structural analyses show that the Ailaoshan-Red River shear zone (ASRRSZ) in Ailao Mountain is composed of three different deformational domains. These domains may represent three episodes of left-lateral slip exper... Structural analyses show that the Ailaoshan-Red River shear zone (ASRRSZ) in Ailao Mountain is composed of three different deformational domains. These domains may represent three episodes of left-lateral slip experienced by the ASRRSZ. The first episode of such deformation occurred throughout the eastern high-grade belt of the ASRRSZ under a transtensional regime and produced L- type tectonites of amphibolite grade. The second episode of left-lateral slip formed high strain zones overprinting the high-grade belt. Its deformational mechanism is similar to simple shear and the deformed rocks are L-S mylonites of greenschist grade. The third episode of left-lateral slip took place chiefly in a western low-grade belt of the ASRRSZ. This deformation occurred in a transpressional regime, formed an overall structure pattern of a sinistral thrust system and produced phyllonites of low-greenschist grade. Geochronological data indicated that the three episodes of left-lateral slip happened before ~58-56 Ma, at least from ~27 Ma to 22 Ma and at ~13-12 Ma respectively. The first episode of slip in the ASRRSZ appeared to correspond to the initial collision of India and Asia at ~60 Ma. The second episode took place almost at the same time as the most intensive compression and uplift in Tibet. The latest event might represent a further eastward material flow in Tibet after ~16-13 Ma. Thus, the ASRRSZ of southeastern Asia probably experienced three main episodes of Tertiary left- lateral slip in the course of intracontinental convergence since the India-Asia collision. 展开更多
关键词 Ailaoshan-Red River shear zone southeastern Asia GEOCHRONOLOGY deformation history India-Asia collision
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The neotectonic deformation and earthquake activity in Zhuanglang river active fault zone of Lanzhou 被引量:1
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作者 袁道阳 刘百篪 +3 位作者 张培震 刘小凤 才树华 刘小龙 《Acta Seismologica Sinica(English Edition)》 CSCD 2002年第4期462-466,共5页
Lanzhou Institute of Seismology, China Seismological Bureau, Lanzhou 730000, China 2) Institute of Geology, China Seismological Bureau, Beijing 100029, China
关键词 Zhuanglang river active fault zone neotectonic deformation fault-propagation fold earthquake activity
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Quantitative analysis on tectonic deformation of active rupture zones
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作者 江在森 牛安福 +4 位作者 王敏 黎凯武 方颖 张希 张晓亮 《Acta Seismologica Sinica(English Edition)》 EI CSCD 2005年第6期656-665,共10页
Based on the regional GPS data of high spatial resolution, we present a method of quantitative analysis on the tectonic deformation of active rupture zones in order to predict the location of forthcoming major earthqu... Based on the regional GPS data of high spatial resolution, we present a method of quantitative analysis on the tectonic deformation of active rupture zones in order to predict the location of forthcoming major earthquakes. Firstly we divide the main fault area into certain deformation units, then derive the geometric deformation and relative dislocation parameters of each unit and finally estimate quantitatively the slip and strain rates in each segment of the rupture zone. Furthermore, by comparing the consistency of deformation in all segments of the whole rupture zone, we can determine the possible anomalous segments as well as their properties and amplitudes. In analyzing the eastern boundaries of Sichuan-Yunnan block with the GPS velocity data for the period of 1991-2001, we have discovered that the Mianning-Ningnan-Dongchuan segment on the Zemuhe-Xiaojiang fault zone is relatively locked and the left-lateral shear strain rate here is higher. 展开更多
关键词 active rupture zone tectonic deformation GPS prediction of strong earthquake location
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FLUID-ROCK INTERACTION AND MASS BALANCE IN DEFORMED ROCKS OF THE IRTISH TECTONIC ZONE,NORTHERN XINJIANG,CHINA
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《Geotectonica et Metallogenia》 1994年第Z2期31-33,共3页
关键词 ROCK FLUID-ROCK INTERACTION AND MASS BALANCE IN deformED ROCKS OF THE IRTISH TECTONIC zone NORTHERN XINJIANG CHINA SiO MNO
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Theoretical simulation of the effect of deformation on local gravity in a density gradient zone 被引量:1
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作者 Zhu Liangyu Wang Qingliang Zhu Yiqing 《Geodesy and Geodynamics》 2013年第4期9-16,共8页
We modeled the effect of the deformation of a Density Gradient Zone (DGZ) on a local gravity field using a cubical model and introduced a new method to simulate a complex DGZ (CDGZ). Then, we analyzed the features... We modeled the effect of the deformation of a Density Gradient Zone (DGZ) on a local gravity field using a cubical model and introduced a new method to simulate a complex DGZ (CDGZ). Then, we analyzed the features of the model for the influence of the deformation of the DGZ on the local gravity field. We concluded that land-based gravity is not sensitive to the thickness of the DGZ and that the magnitude of the contribution of the DGZ is one order less than that of the volume strain with the same displacement. 展开更多
关键词 Density Gradient zone (DGZ) density interface cubical model vertical deformation gravity anomaly
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中亚成矿域西部早二叠世金、镍重大成矿事件
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作者 薛春纪 赵晓波 +9 位作者 赵云 赵伟策 莫宣学 肖文交 马华东 朱炳玉 Nikolay Pak Bakhtiar Nurtaev 邓军 侯增谦 《矿床地质》 CAS CSCD 北大核心 2024年第4期749-784,共36页
晚古生代是地球历史上一个重要时期,蕴含着潘吉亚超大陆、规模最大冰期、最严重的生物大灭绝以及巨量矿产资源形成的关键信息。地处欧亚大陆腹地的中亚成矿域是全球最大的显生宙大陆增生区,以晚古生代大规模成矿为显著特色,尤其早二叠世... 晚古生代是地球历史上一个重要时期,蕴含着潘吉亚超大陆、规模最大冰期、最严重的生物大灭绝以及巨量矿产资源形成的关键信息。地处欧亚大陆腹地的中亚成矿域是全球最大的显生宙大陆增生区,以晚古生代大规模成矿为显著特色,尤其早二叠世(270~290 Ma)在中亚成矿域西部天山及邻区巨量金、镍爆发性集中成矿作用,造就出世界第二大金成矿省,形成了超过10000 t金,造就出具有世界特色的造山带岩浆型镍矿集区,形成了包括8个大型-超大型矿床在内的东天山、额尔齐斯、北山3个重要镍矿床集中区,镍资源达250万t,是一次全球罕见的金-镍时间耦合重大成矿事件。文章基于最新研究成果,系统论述了中亚成矿域西部早二叠世金、镍大规模成矿的时空分布和基本地质特征,探讨了该重大成矿事件的区域动力学背景和可能成矿机制。研究认为,早二叠世金矿床产于天山古缝合带附近的脆/韧性构造变形带,构成独具特色的大陆变形带金成矿系统,已有成矿理论难以涵盖,含碳碎屑岩系、地块抬升导致的大规模区域变质作用、多来源的流体作用、多期构造活化富集、多种因素耦合叠加等,可能是大规模金成矿的关键条件;早二叠世镍矿床沿天山、北山、阿尔泰地区深大断裂附近的镁铁-超镁铁质岩体线性展布,是全球造山带镍成矿作用最强烈、发现矿床数量最多的地区,俯冲熔/流体的交代岩石圈地幔/软流圈发生高程度部分熔融、区域超壳深断裂为玄武质岩浆提供快速运移的通道、壳源物质加入触发硫化物熔离、硫化物与多幕脉动侵位的岩浆反应是造山带岩浆型镍大规模成矿的关键。整体上,中亚成矿域西部早二叠世金、镍重大成矿事件表现为“时间耦合、西金东镍”的时空格局,但大规模成矿的全球和区域动力学背景、金与镍富集机制及成矿响应机理还是未解之谜。 展开更多
关键词 早二叠世 大陆变形带金成矿系统 造山带岩浆型镍成矿系统 重大成矿事件 中亚成矿域西部
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复杂构造变形区断控裂缝发育分布模式
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作者 鞠玮 杨慧 +3 位作者 侯贵廷 宁卫科 李永康 梁孝柏 《地学前缘》 EI CAS CSCD 北大核心 2024年第5期130-138,共9页
天然裂缝是油气重要的储集空间和渗流通道。在复杂构造变形区,裂缝明显受断层影响控制,但其规律和模式尚不清晰。为此,本次研究以库车坳陷为例,通过现场地质观测、成像测井裂缝解译和理论分析,计算断控裂缝系数,揭示走滑断层、逆冲断层... 天然裂缝是油气重要的储集空间和渗流通道。在复杂构造变形区,裂缝明显受断层影响控制,但其规律和模式尚不清晰。为此,本次研究以库车坳陷为例,通过现场地质观测、成像测井裂缝解译和理论分析,计算断控裂缝系数,揭示走滑断层、逆冲断层控制复杂构造变形区天然裂缝的规律,提出断控裂缝发育分布模式。结果表明:(1)逆冲断层对天然裂缝产状和发育程度均具有明显的控制作用,裂缝密度与距断层距离呈现负指数关系,距断层由近及远可以划分为断层强控制裂缝带、断层弱控制裂缝带和区域裂缝带。(2)走滑断层包括调节走滑断层和逆冲走滑断层。调节走滑断层与地层走向近垂直或大角度斜交,发育断层控制裂缝带,其受断层规模影响显著;逆冲走滑断层与地层走向近平行或者小角度斜交,天然裂缝主要局限于断层带内,沿断层走向断裂带宽度发生变化。(3)定义断控裂缝系数(K),即断层强控制裂缝带宽度与断层断距(滑距)的比值,通过分析,库车坳陷逆冲断层K值为1.50~1.80,走滑断层K值为0.125~0.150。研究成果对复杂构造变形区油气勘探开发具有理论和实践指导意义。 展开更多
关键词 裂缝发育分布模式 断控裂缝系数 走滑断层 复杂构造变形区 库车坳陷
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CHARACTERIZATION OF DEFORMATION AND X-RAY PETROFABRICS IN THE MIDDLE PART OF THE WAHONGSHAN FAULT ZONE, QINGHAI PROVINCE, NORTHWESTERN CHINA
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作者 ZHANG Shuanhong ZHOU Xianqiang 《Geotectonica et Metallogenia》 2004年第1期53-65,共13页
The Wahongshan fault zone in Qinghai province is one of the most important faults in western China. In this paper, deformation and X-ray petrofabrics have been studied in the middle segment of the fault. The results s... The Wahongshan fault zone in Qinghai province is one of the most important faults in western China. In this paper, deformation and X-ray petrofabrics have been studied in the middle segment of the fault. The results show that the formation of the fault zones can be divided into two major stages: ductile shear deformation stage and brittle deformation stage. The early stage ductile shearing leads to the formation of the NW-NNW trending mylonite zones along the fault, which is intensely cut by the late-formed brittle faults. X-ray petrofabrics of rocks near the faults indicate that the minerals in the tectonites show a great degree of orientation in the alignment. The quartz, which is a very important mineral in the tectonites, is deformed by basal face gliding or near basal face gliding, and sometimes by prismatic face sliding, which indicates that the rocks are deformed in epithermal to mesothermal or mesothermal environment, and the dynamic recrystallization also plays an important role in the formation of the quartz alignment. The results also demonstrate that plutons formed in the Hercynian and Indosinian stages show no great ductile deformation as can be seen from the X-ray petrofabrics, so it is concluded that these rocks are formed after the formation of the ductile shear zones. Results of Structural deformation analysis and isotope geochronologic analysis of syntectonic muscovite indicate that Wahongshan ductile shear zones are formed in the late Silurian Period during the late Caledonian stage. 展开更多
关键词 structural deformATION X-RAY petrofabric Wahongshan fault zoneS QINGHAI the TibetPlateau
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大凉山背斜核部区隧道初支大变形机理与控制 被引量:1
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作者 梁斌 陈诺 +1 位作者 苗景川 李文杰 《河南科技大学学报(自然科学版)》 北大核心 2024年第2期78-86,M0007,共10页
针对大凉山2号公路隧道穿越高地应力背斜核心区域,隧道易发生初支大变形、坍塌、钢架扭曲等问题,通过现场监控量测、围岩岩性实验、理论分析、数值模拟分析和围岩接触压力监测等综合分析,研究了大凉山2号隧道背斜核部大变形成因机理。... 针对大凉山2号公路隧道穿越高地应力背斜核心区域,隧道易发生初支大变形、坍塌、钢架扭曲等问题,通过现场监控量测、围岩岩性实验、理论分析、数值模拟分析和围岩接触压力监测等综合分析,研究了大凉山2号隧道背斜核部大变形成因机理。研究表明:背斜核部玄武岩单轴抗压强度为23.31 MPa,凝灰质泥岩遇水具有一定膨胀性,给围岩变形创造了条件。由于岩层岩性不同,开挖后洞周玄武岩呈独立受弯剪梁状态。相对无水条件下,受地下水补给影响,围岩塑性区面积增加,拱腰部位较为明显。加固前,拱顶沉降量最大达470 mm,拱腰最大收敛值为844 mm,围岩接触压力为523.47 kPa。采用双层小导管+中台阶临时支撑+边墙临时支撑的“主动适应+强支撑”的综合处置方式,隧道拱顶变形减少87.6%,水平收敛变形减少95%,围岩接触压力最大值降至128 kPa,隧道变形得到有效控制。 展开更多
关键词 隧道工程 背斜核部区 大变形机理 现场监测 岩性实验 数值模拟
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冀东金厂峪金矿剪切带控矿规律及找矿建议
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作者 鄂建新 缪广 +2 位作者 宁腾霄 郭运晨 张强 《世界有色金属》 2024年第1期82-84,共3页
冀东金厂峪金矿为典型受构造作用控制的矿床,金矿体主要产于NNE向脆-韧性片理化带内的强变形带之中,直接控矿构造为叠加于强变形带之上的NNE向燕山期脆性断裂构造。本文在详细的野外调查基础上进行了构造分期配套,建立了弱变形域控岩+... 冀东金厂峪金矿为典型受构造作用控制的矿床,金矿体主要产于NNE向脆-韧性片理化带内的强变形带之中,直接控矿构造为叠加于强变形带之上的NNE向燕山期脆性断裂构造。本文在详细的野外调查基础上进行了构造分期配套,建立了弱变形域控岩+强变形带赋矿的透镜体控矿模式,结合矿体赋存和矿化富集规律总结,提出了韧脆性片理化带深部、两侧次级平行构造等找矿方向。 展开更多
关键词 冀东 金厂峪金矿 脆-韧性变形 片理化带 强变形带 弱变形域
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覆岩导水裂隙带发育高度动态演化规律研究 被引量:2
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作者 赵兵朝 冯杰 +3 位作者 赵阳 侯恩科 马云祥 冯欣怡 《煤矿安全》 CAS 北大核心 2024年第2期176-183,共8页
为了研究覆岩导水裂隙带发育高度动态演化规律,以小保当矿区2^(-2)煤层为研究对象,通过理论分析、相似模拟实验及实例验证的方法,对导水裂隙带动态发育高度进行研究;借助概率积分法预计其上部岩层移动变形的理论公式,给出了1种基于覆岩... 为了研究覆岩导水裂隙带发育高度动态演化规律,以小保当矿区2^(-2)煤层为研究对象,通过理论分析、相似模拟实验及实例验证的方法,对导水裂隙带动态发育高度进行研究;借助概率积分法预计其上部岩层移动变形的理论公式,给出了1种基于覆岩曲率变形的导水裂隙带动态发育高度预计方法。研究表明:导水裂隙带上部岩层下沉系数是1个与挠度及下部自由空间高度相关的分段函数,上部岩层曲率变形大小是决定导水裂隙带发育高度的关键因素;导水裂隙带发育高度与工作面推进长度相关;理论预计小保当矿区2^(-2)煤层导水裂隙带发育高度为160.8 m,相似模拟实验发育高度为155 m,现场实测发育高度为152.01~175.57 m。 展开更多
关键词 导水裂隙带 动态演化 下沉系数 曲率变形 概率积分法
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穿断层破碎带隧道围岩大变形控制双梯度注浆机制
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作者 陶志刚 孙吉浩 +3 位作者 曹振生 胡才 郭隆基 何满潮 《隧道建设(中英文)》 CSCD 北大核心 2024年第6期1194-1213,I0023-I0042,共40页
近些年,中国西部大量深埋隧道工程因关键线路控制无法避让一些活动性断裂,常常在跨越断裂带范围内出现围岩大变形破坏现象,例如侵限、偏压、塌方、底鼓等灾害,严重影响隧道工程施工和运营的安全可持续发展。为了控制断层破碎带隧道围岩... 近些年,中国西部大量深埋隧道工程因关键线路控制无法避让一些活动性断裂,常常在跨越断裂带范围内出现围岩大变形破坏现象,例如侵限、偏压、塌方、底鼓等灾害,严重影响隧道工程施工和运营的安全可持续发展。为了控制断层破碎带隧道围岩大变形,隧道工程设计者和建设者采用了多种控制方案,例如超前注浆、多层钢拱架被动支护、锚杆索主动支护等,但是都因断层破碎带围岩强度过低而出现超前注浆诱发围岩拉裂破碎、主动支护锚杆锚固力不足等现象。为解决上述难题,首先,提出一种增强穿断层破碎带隧道围岩强度的双梯度注浆技术,建立双梯度注浆概念模型,构建3种双梯度注浆模式;然后,确定特定工况下注浆材料粒径梯度与注浆压力梯度的适配条件;最后,通过理论分析、物理模型试验和现场试验,探索双梯度注浆机制及其控制效果。研究结果表明:1)随着开挖步序的增加,穿断层破碎带隧道拱肩变形最大,构造应力对围岩稳定性影响较大。2)在双梯度注浆作用下,浆液扩散效果良好,围岩未出现大面积脱落破坏,隧道周围岩体应力分布均匀。3)双梯度注浆形成了坚硬交叉浆脉骨架,达到了应力补偿效果,将围岩变形量从原来的3 100 mm控制到278 mm以内,实现了“零换拱、零侵限、零突涌”的目标。 展开更多
关键词 隧道 断层破碎带 围岩大变形 双梯度注浆 开挖补偿法
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2022年泸定M_(S)6.8地震震前区域变形背景及同震形变特征
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作者 徐晶 季灵运 刘传金 《地震地质》 EI CSCD 北大核心 2024年第3期645-664,共20页
文中利用Sentinel-1 SAR影像获取了2022年泸定6.8级地震的震间形变场(2014—2020年)和同震形变场,估算了泸定地震的震间断层滑动速率、闭锁深度和同震滑动分布,分析了此次地震对周边断裂的影响,并进一步探讨泸定地震的发震构造和磨西断... 文中利用Sentinel-1 SAR影像获取了2022年泸定6.8级地震的震间形变场(2014—2020年)和同震形变场,估算了泸定地震的震间断层滑动速率、闭锁深度和同震滑动分布,分析了此次地震对周边断裂的影响,并进一步探讨泸定地震的发震构造和磨西断裂及其周边断裂的未来地震发生趋势。震间InSAR形变场及InSAR和GNSS融合的三维形变场结果显示了2022年泸定地震发震断层的长期滑动特征,滑动速率为(5.9±1.8)mm/a,主要表现为剪切变形明显且应变集中的特征,震前磨西断裂存在明显闭锁,具有强震发生背景。同震滑动分布反演结果表明,此次泸定地震是以左旋走滑为主的高倾角走滑地震,最大滑动量可达1.71m,最大滑动位于10km深处。基于文中获得的同震滑动分布计算了同震位错效应引起的断层面上的库仑应力变化,结果显示磨西断裂南段的地震破裂段形成应力影区,而在此次地震中未破裂的北段的库仑应力显著升高,同时,折多塘断裂南东部分、安宁河断裂带石棉—冕宁段北西部分、大凉山断裂竹马段南东部分和公益海段南东部分的断层面库仑应力显著增加。2022年泸定地震的发震构造为鲜水河断裂带的磨西断裂,此次泸定地震的发生并没有完全降低鲜水河断裂带的地震风险,仍需重点关注磨西断裂未破裂段及其周边具有大地震发生背景的强震破裂空段。 展开更多
关键词 2022年泸定地震 鲜水河断裂带 震间形变 同震滑动分布 库仑应力变化 地震危险性
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软土地区大型基坑平行分区研究
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作者 黄沛 刘青 +1 位作者 石海丽 张亚国 《工程地质学报》 CSCD 北大核心 2024年第5期1850-1859,共10页
为了给软土地区大型基坑平行分区的设计和施工提供理论依据,结合软土地区大型基坑平行分区典型分区参数,建立数值计算模型,对分区后邻近被保护建/构筑物一侧围护墙的水平位移、地表沉降以及坑外土体沉降和水平位移进行分析,在此基础上... 为了给软土地区大型基坑平行分区的设计和施工提供理论依据,结合软土地区大型基坑平行分区典型分区参数,建立数值计算模型,对分区后邻近被保护建/构筑物一侧围护墙的水平位移、地表沉降以及坑外土体沉降和水平位移进行分析,在此基础上研究大型基坑平行分区控制变形的机理。研究结果表明:分区后的围护墙顶部的水平位移比未分区的稍大,围护墙最大水平位移深度与未分区相近,但围护墙最大水平位移比未分区时减小31.1%;分区后最大地表沉降位置比未分区时更接近基坑,最大地表沉降比未分区时减小35.1%;围护墙的水平位移、地表沉降和坑外土体变形主要由邻近狭窄基坑开挖引起;分区后土体内部沉降、水平位移和坑底隆起影响深度均小于未分区时的值。分区后,在远处大面积基坑开挖过程中,基坑外侧围护墙凭借其较大的刚度,对土体变形具有较强的遮拦效应;近处小面积基坑开挖时,可以充分利用基坑宽度较小时开挖引起的变形也较小的规律;大面积基坑分区开挖符合基坑变形时空效应理论的要求。平行分区可以充分利用基坑外侧围护墙对变形的遮拦、基坑宽度对基坑变形的影响以及基坑变形的时空效应,从而使得平行于分隔墙一侧的围护结构变形和地表沉降大幅减小。 展开更多
关键词 基坑工程 分区开挖 沉降 软土 变形控制
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基于位移等代法的深部直墙半圆拱形隧洞松动圈厚度预测
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作者 邵炜星 查文华 +2 位作者 许涛 王荣荣 程文博 《水利水电技术(中英文)》 北大核心 2024年第3期140-147,共8页
【目的】位移等代法是在工程实践中被广泛应用的一种等效圆法。为进一步探索该方法在深部非均匀应力场下预测松动圈厚度的工程效果,并建立具有工程适用性的等效圆半径计算公式,【方法】选取深部隧洞常采用的直墙半圆拱形断面为研究对象... 【目的】位移等代法是在工程实践中被广泛应用的一种等效圆法。为进一步探索该方法在深部非均匀应力场下预测松动圈厚度的工程效果,并建立具有工程适用性的等效圆半径计算公式,【方法】选取深部隧洞常采用的直墙半圆拱形断面为研究对象,根据位移等代法基本原理,利用FLAC~(3D)数值模拟和理论计算相结合的方式,建立了侧压系数λ为1.1~1.5,跨高比b_0/h为1.3~1.5条件下的等效圆半径函数关系式,并应用到江西曲江某煤矿水仓围岩的松动圈厚度预测。【结果】结果显示:根据等效圆公式计算出的水仓围岩松动圈的纵轴厚度为1.41 m,横轴为1.20 m,呈椭圆形;现场实测的松动圈也呈椭圆形,厚度平均值在1.15~1.45 m,其中最大均值在纵轴1.45 m,最小均值在横轴为1.15 m。理论预测值与实测值相吻合。【结论】结果表明:位移等代法适用于深部软岩松动圈厚度预测;所建等效圆半径公式具有良好的工程适用性,可为评价和预测类似隧洞工程松动圈厚度提供一种简化的、可借鉴的方法和思路。 展开更多
关键词 隧洞 直墙半圆拱形 位移等代法 等效圆 围岩 变形 松动圈 数值模拟
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节点域承载力对半刚性钢框架地震易损性影响研究
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作者 隋伟宁 王鹏辉 +1 位作者 黄鲁东 董峥 《沈阳建筑大学学报(自然科学版)》 CAS 北大核心 2024年第1期78-85,共8页
目的 通过考察节点域承载力变化与地震易损性曲线间的关系,获得半刚性钢框架地震易损性曲线,量化节点域屈服承载力对半刚性钢框架地震易损性的影响。方法 采用OpenSEES抗震分析软件建立以节点域承载力比为主要参数的半刚性钢框架模型,... 目的 通过考察节点域承载力变化与地震易损性曲线间的关系,获得半刚性钢框架地震易损性曲线,量化节点域屈服承载力对半刚性钢框架地震易损性的影响。方法 采用OpenSEES抗震分析软件建立以节点域承载力比为主要参数的半刚性钢框架模型,通过地震需求分析和抗震能力分析,绘制不同节点域屈服承载力比(0.5~1.0)对应的半刚性钢框架地震易损性曲线。结果 节点域屈服承载力比的取值为0.7时,半刚性钢框架地震易损性曲线在四种极限状态下均小于其他半刚性钢框架,且形成包络趋势。结论 在水平地震作用下,允许节点域屈服,可显著降低钢框架的失效概率,结构的抗震性能也得到了明显改善;节点域屈服承载力比取0.7时,结构抗震性改善效果最显著。 展开更多
关键词 节点域 剪切变形 易损性分析 抗震性能 弹塑性动力时程分析
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