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Experimental study on failure evolution mechanism of clastic rock considering cementation and intermediate principal stress

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Journal of Rock Mechanics and Geotechnical Engineering 2023年第7期15卷 1636-1650页

作者： Feiyan Wang Xia-Ting Feng Yangyi Zhou Xiaojun Yu Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines School of Resources and Civil EngineeringNortheastern UniversityShenyang110819China Key Laboratory of Liaoning Province on Deep Engineering and Intelligent Technology Northeastern UniversityShenyang110819China

The study of clastic rock failure evolution under true triaxial stress is an important research topic;however,it is rarely studied systematically due to the limitation of monitoring technology.In this study,true triaxial compression tests were conducted on clastic rock specimens to investigate the effect of cementation and intermediate principal stress(s2)on the failure mechanism.The complete stressestrain curves were obtained,while the acoustic emission(AE)was monitored to indirectly evaluate the evo-lution of tensile and shear cracks,and crack evolution under true triaxial compression was imaged in real time by a high-speed camera.The results showed that the deformation and failure characteristics of clastic rock were closely related to the cementation type and intermediate principal stress.On the basis of the distribution characteristics of the ratio of rise time to amplitude(RA)and the average frequency(AF)of AE signals,tensile cracks of the contact cementation specimen propagated preferentially.Meanwhile,the enhancement of specimen cementation promoted the evolution of shear cracks,and the increase inσ_(2)promoted the evolution of tensile cracks.Moreover,the mesoscale cracking mechanism of clastic rock caused by cementation andσ_(2)under true triaxial compression was analyzed.The failure patterns of clastic rock under true triaxial compression were divided into three modes:structure-induced,structure-stress-induced and stress-induced failures.This study confirms the feasibility of high-speed camera technology in true triaxial testing,and has important implications for elucidating the disaster mechanism of deep tunnels in weak rocks.

关键词： True triaxial compression cementation Failure evolution Acoustic emission(AE) High-speed camera

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Site observations of weathered granitic soils subjected to cementation and partial drainage using SCPTU

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Journal of Rock Mechanics and Geotechnical Engineering 2023年第4期15卷 984-996页

作者： Xianwei Zhang Xinyu Liu Ran An Xinming Li State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China University of Chinese Academy of Sciences Beijing100049China College of Urban Construction Wuhan University of Science and TechnologyWuhan430065China School of Civil Engineering and Architecture Zhongyuan University of TechnologyZhengzhou450007China

Because of the cementation inherited from the parent rock,weathered granitic soil is usually susceptible to disturbance,which poses considerable challenges for laboratory characterization.The cone penetration test with pore pressure measurements has long been known for its reliability in site investigations and stratigraphic profiling.However,although extensive piezocone test results and experience are available for sedimentary soil,similar advances are yet to be made for weathered granitic soil.Moreover,the experience from sedimentary soil may not be directly applicable to weathered profiles because of the essentially different natures of the two types of geomaterials.This study performs seismic piezocone tests in a weathered granitic profile comprising residual granitic soil,completely weathered granite,and highly weathered granite.Pore pressure is measured at both the cone mid-face and the shoulder,and the effects of penetrometer size and penetration rate are considered.A series of updated soil behavior type charts is proposed to interpret the test results,thereby allowing the effect of weathering to be evaluated.This paper offers an important extension to the sparse data on the in situ responses of weathered materials.

关键词： Weathered granite Seismic piezocone test cementation Soil classification Pore pressure Weathering degree

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cementation Characteristics and Their Effect on Quality of the Upper Triassic, the Lower Cretaceous, and the Upper Cretaceous Sandstone Reservoirs, Euphrates Graben, Syria

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Journal of Earth Science 2021年第6期32卷 1545-1562页

作者： Ibrahem Yousef Vladimir Morozov Vladislav Sudakov Ilyas Idrisov Institute of Geology and Petroleum Technologies Kazan Federal UniversityKazanRussia

This article presents the results of cementation characteristics and their effect on sandstone reservoir quality of the Upper Triassic Mulussa F, the Lower Cretaceous Lower Rutbah, and the Upper Cretaceous Post Judea Sandstone formations in selected fields in the Euphrates Graben area, Syria. This study emphasises the role of cementation in the evaluation of the diagenetic history of the sediments, developing effective porosity, as well as evaluation of reservoirs stimulation procedures and potential for formation damage of the sandstone reservoirs. Quartz cement is present as well developed tabular or pyramidal syntaxial overgrowths. Kaolinite cement is present as vermicular aggregates which are most abundant within sandstones of the Mulussa F Formation. Carbonate cements include siderite and dolomite. Four lithofacies were identified within the studied formations;lithofacies-1 and 2 correspond to fluvial depositional environments, lithofacies-3 and 4 correspond to fluvial to estuarine channel environments. The Post Judea Sandstone and the Lower Rutbah reservoir units are typically lithofacies-3 sequences in which quartz overgrowths are the dominant cement. Because the total cement is more extensive in the Post Judea Sandstone Formation than in the Lower Rutbah Formation, resulting in high porosity(up to 26%) and permeability(6 000 mD), the reservoir quality is predicted to be best in the Post Judea Sandstone Formation. The reservoir units in the Mulussa F Formation contain the highest cement volumes comprised of early siderite and kaolinite, which, with the development of compaction-resisting quartz overgrowths and resultant compactional pore volume loss, has resulted in typically lower porosity being preserved than in the Lower Rutbah and Post Judea Sandstone formations.

关键词： cementation diagenesis reservoirs quality Euphrates Graben Syria

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Numerical Simulation of the Influence of Pore Structure on Resistivity, Formation Factor and cementation Index in Tight Sandstone

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Acta Geologica Sinica(English Edition) 2020年第2期94卷 290-304页

作者： WU Feng WEN Zhu YAO Cong WANG Xianhu XI Yanping CONG Linlin State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengdu 610500China Shandong Provincial Key Laboratory of Depositional Mineralization&Sedimentary Mineral Shandong University of Science and TechnologyQingdao 266590China School of Geoscience and Technology Southwest Petroleum UniversityChengdu 610500China No.1 Mudlogging Company Bohai Drilling Engineering CompanyChina National Petroleum Corporation.Tianjing 300280China Logging Research Institution of Xinjiang Branch China National Petroleum CorporationKaramayXinjiang 834000China

Tight sandstone,with severe diagenesis and complex pore structure,differs greatly from conventional sandstone in terms of rock electrical parameters.In subsurface rock electrical experiments,various electrical parameters are confounded and can only be analyzed qualitatively.The lack of quantitative analysis for each individual electrical parameter presents a challenge for the evaluation of oil and gas saturation in tight sandstone.Based on the 2D pore-throat model and the features of pore structure in the tight sandstone of the Penglaizhen and Shaximiao Formations in the upper and middle Jurassic of the Western Sichuan Depression,this paper presents 3D micro pore-throat models for three types of tight sandstone.It proposes a finite element-based rock electrical simulation method to analyze the influence of pore structure parameters,such as throat radius and throat tortuosity,on electrical parameters such as resistivity,formation factor,and cementation index quantitatively.The research revealed the following results:(1)Throats of tight sandstone usually have lamellar or curved lamellar shapes that are slender and narrow.The lamellar throat used in the proposed porethroat model is more consistent with the features of tight sandstone than the tubular throat used in the original model.(2)The throat determines the conductivity of tight sandstone.The throat parallel to the electric potential has the greatest influence on conductivity,and the throat perpendicular to the potential has the least influence.(3)In tight sandstone grades I to III,as the porosity decreases,the formation factor increases and the cementation index decreases.(4)The results of the rock electrical simulation are consistent with the results of the rock electrical experiment,which indicates that the proposed rock electrical simulation method of tight sandstone is effective and accurate.

关键词： tight sandstone resistivity formation factor cementation index numerical simulation western Sichuan Depression

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Study of Fractal Characteristics of the cementation Index in Shale Gas

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Acta Geologica Sinica(English Edition) 2020年第2期94卷 456-466页

作者： LIU Hongqi LIU Shiqiong LUO Xingping SUN Yangsha TIAN Jie LIANG Lixi LIU Xiangjun School of GeoScience and Technology Southwest Petroleum UniversityChengdu 610500China Institute of exploration and development Petrochina Xinjiang oilfield company.Junggar road 29#.KaramayXinjiangChina College of Petroleum Engineering.Southwest Petroleum University Chengdu 610500China

The description of pores and fracture structures is a consistently important issue and certainly a difficult problem, especially for shale or tight rocks. However, the exploitation of so-called unconventional energy, such as shale methane and tight-oil, has become more and more dependent on an understanding of the inner structure of these unconventional reservoirs. The inner structure of porous rocks is very difficult to describe quantitatively using normal mathematics, but fractal geometry, which is a powerful mathematical tool for describing irregularly-shaped objects, can be applied to these rocks. To some degree, the cementation index and tortuosity can be used to describe the complexity of these structures. The cementation index can be acquired through electro-lithology experiments, but, until now, tortuosity could not be quantitatively depicted. This research used the well-logging curves of a gas shale formation to reflect the characteristics of the rock formations, and the changes in the curves to indicate the changes of the rock matrix, the pores, the connections among the pores, the permeability, and the fluid type. The curves that are affected most by the rock lithology, such as gamma ray, acoustic logging, and deep resistivity curves, can provide significant information about the micro-or nanostructure of the rocks. If the rock structures have fractal characteristics, the logging curves will also have fractal properties. Based on the definition of a fractal dimension and the Hausdorff dimension, this paper presents a new methodology for calculating the fractal dimensions of logging curves. This paper also reveals the deep meaning of the rock cementation index, m, through the Hausdorff dimension, and provides a new equation to calculate this parameter through the resistivity and porosity of the formation. Although it represents a very important relationship between the saturation of hydrocarbons with pores and resistivity, the Archie formula was not available for shale and tight rock. The major reason f

关键词： fractal geometry nano-scale well-logging curve cementation index tight rocks gas shale

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SELECTIVE RECOVERY OF SILVER FROM AN ACIDIC SOLUTION BY cementation WITH COPPER

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Journal of Central South University 1998年第2期10卷 40-43页

作者： Yongbin Yang Tao Jiang Ganghua Fu Boquan He Zhucheng Huang 1. Department of Mineral Engineering Central South University of Technology 410083 Changsha China

Ｉｎｔｒｅａｔｉｎｇａｍａｎｇａｎｅｓｅ－ｓｉｌｖｅｒｏｒｅｂｙｌｅａｃｈｉｎｇｉｎａｃｉｄｉｃｍｅｄｉｕｍｗｉｔｈａｎａｄｄｉｔｉｖｅＲＨ［１，２］，ｍａｎ－ｇａｎｅｓｅａｎｄｓｉｌｖｅｒｗｅｒｅｓｉｍｕｌｔａｎｅ... 详细信息

Ｉｎｔｒｅａｔｉｎｇａｍａｎｇａｎｅｓｅ－ｓｉｌｖｅｒｏｒｅｂｙｌｅａｃｈｉｎｇｉｎａｃｉｄｉｃｍｅｄｉｕｍｗｉｔｈａｎａｄｄｉｔｉｖｅＲＨ［１，２］，ｍａｎ－ｇａｎｅｓｅａｎｄｓｉｌｖｅｒｗｅｒｅｓｉｍｕｌｔａｎｅｏｕｓｌｙｄｉｓｓｏｌｖｅｄａｎｄ...

关键词： extraction cementation silver

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Estimation of thermal conductivity of cemented sands using thermal network models

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Journal of Rock Mechanics and Geotechnical Engineering 2022年第1期14卷 210-218页

作者： Wenbin Fei Guillermo A.Narsilio Department of Infrastructure Engineering The University of MelbourneParkvilleAustralia

Effective thermal conductivity of soils can be enhanced to achieve higher efficiencies in the operation of shallow geothermal systems.Soil cementation is a ground improvement technique that can increase the interparticle contact area,leading to a high effective thermal conductivity.However,cementation may occur at different locations in the soil matrix,i.***.interparticle contacts,evenly or unevenly around particles,in the pore space or a combination of these.The topology of cementation at the particle scale and its influence on soil response have not been studied in detail to date.Additionally,soils are made of particles with different shapes,but the impact of particle shape on the cementation and the resulting change of effective thermal conductivity require further research.In this work,three kinds of sands with different particle shapes were selected and cementation was formed either evenly around the particles,or along the direction parallel or perpendicular to that of heat transfer.The effective thermal conductivity of each sample was computed using a thermal conductance network model.Results show that dry sand with more irregular particle shape and cemented along the heat transfer direction will lead to a more efficient thermal enhancement of the soil,i.e.a comparatively higher soil effective thermal conductivity.

关键词： Network cementation Computed tomography Ground improvement Sands

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Copper Oxide Ore Leaching Ability and cementation Behavior, Mesgaran Deposit in IRAN

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Open Journal of Geology 2018年第9期8卷 841-858页

作者： Shayan Khakmardan Aref Shirazi Adel Shirazy Hassan Hosseingholi AmirKabir University of Technology (Tehran Polytechnic) Tehran Iran Shahrood University of Technology Shahrood Iran Sormak Mining Company Tehran Iran

One of the Iranian copper deposits that is located east of Iran and also known as a primeval one in that area is Mesgaran Field. Old mining works have been clearly seen in the area. Iran is located on global copper belt and as a result it has numerous potential areas as copper deposits. The purpose of this study is identifying possible potentialities of copper mining in less developed regions of Iran with basic modern technologies. In this study, laboratory investigations of this field were done on samples via leaching and the cementation method. According to the study purposes, acid concentration, temperature, time and pulp density were selected as the main factors that were tested in leaching studies. Moreover, pH, temperature, time and the amount of iron powder were factors which were tested for copper cementation. Optimum conditions of leaching studies with 99.11% recovery rate were obtained after 120 grams per liter of H2SO4, 80 degrees Celsius, 2 hours and 100 grams per liter of solid to liquid. On the other hand, optimum conditions of cementation by iron powder were resulted at more than 95% with a pH of 3, 45 degrees Celsius, 1 hour and 1.5 times more than the stoichiometric equation of required iron powder amount to precipitate copper.

关键词： Leaching cementation Copper Oxide Malachite VMS Copper Deposit

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How to Fill the Cavity after Curettage of Giant Cell Tumors around the Knee？ A Multicenter Analysis

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Chinese Medical Journal 2017年第21期130卷 2541-2546页

作者： Kai Zheng Xiu-Chun Yu Yong-Cheng Hu Zhen Wang Su-Jia Wu Zhao-Ming Ye Giant Cell Tumor Group of China (GTOC) Department of Orthopaedics The General Hospital of Jinan Military Commanding Region Jinan Shandong 250031 China Department of Bone Oncology Tianjin Hospital Tianjin 300211 China Department of Orthopaedics Xijing Hospital The Fourth Military Medical University Xi&#39 an Shaanxi 710032 China Department of Orthopaedics Jinling Hospital Clinical School of Medical College Nanjing University Nanjing Jiangsu 210000 China Department of Orthopaedics The Second Affiliated Hospital School of Medicine Zhejiang University Hangzhou Zhejiang 310009 China

Background： Intralesional excision with curettage is the standard method of giant cell tumor （GCT） treatment, but the ideal filling material after curettage remains controversial. The purpose of this study was to compare the oncological and functional outcomes which underwent cementation or bone grafting after GCT curettage around the knee. Methods： We reported 136 cases with GCTs in distal femur or proximal tibia who accepted curettage from five clinical centers during the last 15 years. All patients were divided into two groups according to filling materials. Recurrence-free survival proportions were used to evaluate oncological outcomes while the Musculoskeletal Tumor Society （MSTS） 93 functional score was used to evaluate functional outcomes. Other parameters including surgical complication, general condition, and radiological classification had been analyzed. The valid statisitical data was analyzed using SPSS 13.0 software. Results： After GCT curettage, 86 patients （63.2%） accepted bone grafting while 50 patients （36.8%） accepted cementation. There was no statistical difference in age, gender, tumor location, radiological classification, fixation, follow-up time, and MSTS 93 functional score between cementation group and bone grafting group. The recurrence-free survival proportions showed that the recurrence rate in bone grafting group was higher than it in cementation group （P = 0.034）. Surgical complication was lower in cementation group than that in bone grafting group but without statistically significant difference （P = 0.141）. Conclusions： Parameters including patients＆#39;age, gender, tumor location, and radiological classification did not affect surgeons＆#39;treatments in cavity filling after GCT curettage. cementation should be recommended because of easy usage, the similar postoperative knee function with bone grafting, and the better local tumor control than bone grafting.

关键词： Bone Grafting cementation Giant Cell Tumor Knee

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Fatigue cyclic loading test of an auro-galvanoforming ceramic bridge

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Chinese Medical Journal 2008年第19期121卷 1896-1899页

作者： ZHANG Xiang-hao SUN Feng WANG Huan XU Man-qiong Outpatient Dental Center Peking University School ot Stomatology Beijing 100034 China Department of Engineering Mechanics Tsinghua University Beijing100084 China

Background In dental clinics, dentition defects are commonly restored with conventional porcelain-fused-to-metal fixed bridges. However, Ni-Cr alloy ceramic fixed bridges are known to have several drawbacks such as marginal coloration of the neck, low casting precision and, most seriously, poor biocompatibility. These problems could be circumvented by using noble metal ceramic bridges; however, one negative issue related to the conventional noble metal ceramic bridges is its high price due to the use of a large amount of gold for pontic. Therefore, an auro-galvanoforming ceramic bridge would be ideal to retain the advantages of a conventional material, yet reduce the amount of noble metal used. This study aimed to investigate whether any destructive changes occur to the auro-galvanoforming ceramic bridge under a fatigue cyclic loading test. Methods On standard models which the left maxillary first premolar is lost and with the cuspid teeth and the second premolar as the fixed bridge abutment teeth, six maxillary auro-galvanoforming ceramic bridges and six corresponding nichrome ceramic jointed crowns were made as group A, six nichrome ceramic bridges and six corresponding nichrome ceramic jointed crowns were made as group B （control group）. And then all specimens were fixed and tested on a fatigue cyclic loading machine; the changes occurring to the surfaces of occlusal contact with large functional area and to the porcelain-metal interfaces of the nichrome primary copings margins were observed through a scanning electron microscope （SEM）. Results In 120 hours＇ continual observation, none of the specimens had porcelain coating fractures or scraping occurrence and all of the porcelain coatings had been kept intact under sinusoidal cyclic loading with the load range of 120-200 N and frequency of 5 Hz. Conclusions Auro-galvanoforming ceramic bridges exhibited excellent fatigue strength in the fatigue cyclic loading test and may satisfy the clinical demand in theory, while the practical application shall be evaluated

关键词： dental occlusion dental prosthesis cementation

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