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Effect of combined mining with steeply dipping seam on stability of surrounding rock of inclined shaft in weakly cemented stratum

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IOP Conference Series: Earth and Environmental Science 2019年第3期237卷

作者： Zhaoyang Song Wen Wei Jie Tan Mine Construction Branch China Coal Research Institute Beijing 100013 China School of Civil and Resource Engineering University of Science and Technology Beijing. Beijing 100083 China Inner Mongolia Fucheng Mining Co. Ltd Erdos 016299 China

The combined mining with steeply dipping seam in weakly cemented stratum causes the original stress in the upper strata to be nonlinearly superimposed on the mining disturbance stress. Although the surrounding rock of the main inclined shaft is outside the designed 'displacement angle', with the extension of the depth of the wellbore and the increase of the volume of the mining, the regional deformation still has an important impact on the stability of the surrounding rock of the wellbore. In view of this, this study established a three-dimensional geological model of the mining area and numerically analyzed the influence of the combined mining of No. 3 coal and No. 9 coal with steeply dipping seam on the surrounding rock stress and deformation of the main inclined shaft. The research shows that the No. 3 coal mining has little influence on the surrounding rock of the main inclined shaft. The distribution of the stress distribution in the main inclined shaft after the No. 3 coal and No. 9 coal mining is redistributed. The stratum stress of the stratum elevation +800~+900m is significantly affected by the mining disturbance, but it has little effect on the stress distribution of the surrounding rock of the main inclined shaft arching stage strata. No. 3 coal seam mining and No. 9 coal seam mining have a greater impact on the position of the main inclined shaft surrounding rock elevation of +950 m, but the overall settlement is still small (maximum 8 mm). Therefore, the influence of underground combined mining disturbance has little effect on the arching stage strata of the main inclined shaft, and the surrounding rock of the main inclined shaft arching stage strata is safe and stable.

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Feasibility of producing unfired four-hole hollow bricks from blended cement-fly ash-chippings under coupled-static forming pressure

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IOP Conference Series: Materials Science and engineering 2019年第1期625卷

作者： Trong-Phuoc Huynh Ngoc-Duy Do Chao-Lung Hwang Si-Huy Ngo Ngoc-Hang Thi Mai Department of Rural Technology College of Rural Development Can Tho University Campus II 3/2 St. Ninh Kieu Dist. Can Tho City 900000 Vietnam Department of Civil Engineering College of Engineering Technology Can Tho University Campus II 3/2 Street Ninh Kieu District Can Tho City 900000 Vietnam Department of Civil and Construction Engineering National Taiwan University of Science and Technology No. 43 Keelung Rd. Da'an Dist. Taipei City 10607 Taiwan Department of Engineering and Technology Hong Duc University No. 565 Quang Trung Street Dong Ve Ward Thanh Hoa City 440000 Vietnam

Unfired four-hole hollow brick (UFHB) is a type of environmental-friendly brick with low energy consumption. However, the using of ordinary Portland cement (OPC) in UFHB is costly and indirectly affects the environment. This paper focuses on an exploratory study on the use of blended fly ash (FA)-OPC in the production of the UFHB and proposes the application of FA-OPC mixtures as a timely solution for the reduction of OPC in UFHB. The 80×80×180 mm UFHB samples were produced using different proportions of FA and OPC under a constant coupled-static forming pressure. The report exhibited experimental characterizations on physical and mechanical properties of both starting materials and UFHB products. In addition, a scanning electron microscope (SEM) analysis was used to evaluate the microstructure of the final UFHB. Test results show that the inclusion of FA in the UFHB mixtures provided positive effects on brick properties. As a result, 10% FA was found as an optimal content, which resulted in the highest brick's strength, the lowest water absorption rate, and a denser microstructure. Furthermore, properties of all of the UFHB samples produced for this study satisfied the requirements of the National Vietnamese standard for non-bearing building brick.

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Comparison of the greenhouse gas emissions of a high-rise residential building assessed with different national LCA approaches – IEA EBC Annex 72

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IOP Conference Series: Earth and Environmental Science 2020年第2期588卷

作者： R Frischknecht L Ramseier W Yang H Birgisdottir Ch U Chae T Lützkendorf A Passer M Balouktsi B Berg L Bragança J Butler M Cellura M Dixit D Dowdell N Francart A García Martínez V Gomes M Gomes Da Silva G Guimaraes E Hoxha M Kjendseth Wiik H König C Llatas S Longo A Lupíšek J Martel R Mateus F Nygaard Rasmussen C Ouellet-Plamondon B Peuportier F Pomponi L Pulgrossi M Röck D Satola B Soust Verdaguer Z Szalay A Truong Nhu J Veselka M Volf O Zara treeze Ltd. Uster Switzerland Tianjin University School of Architecture Tianjin China Aalborg University Danish Building Research Institute Copenhagen Denmark Korea Institute of Civil Engineering and Building Technology Gyeonggi-do Republic of Korea Karlsruhe Institute of Technology Karlsruhe Germany Graz University of Technology Graz Austria BRANZ Porirua New Zealand University of Minho Civil Engineering Guimarães Portugal University of Palermo Palermo Italy Texas A&M University Construction Science College Station USA KTH Royal Institute of Technology Stockholm Sweden Universidad de Sevilla Construcciones Arquitectónicas I. Seville Spain University of Campinas GBLab Campinas Brazil Federal University of Espírito Santo Vitoria Brazil SINTEF Building and Infrastructure Oslo Norway Ascona Gröbenzell Germany Czech Technical University in Prague University Centre for Energy Efficient Buildings Prague Czech Republic Groupe Ageco Montreal Canada École de technologie supérieure Génie de la construction Montreal Canada MINES ParisTech Centre Efficacité énergétique des Systèmes Paris France Edinburgh Napier University Resource Efficient Built Environment Lab Edinburgh Scotland NTNU – Norwegian University of Science and Technology Trondheim Norway Budapest University of Technology and Economics Budapest Hungary

Introduction: The international research project IEA EBC Annex 72 investigates the life cycle related environmental impacts caused by buildings. The project aims inter alia to harmonise LCA approaches on buildings. Methods: To identify major commonalities and discrepancies among national LCA approaches, reference buildings were defined to present and compare the national approaches. A residential high-rise building located in Tianjin, China, was selected as one of the reference buildings. The main construction elements are reinforced concrete shear walls, beams and floor slabs. The building has an energy reference area of 4566 m2 and an operational heating energy demand of 250 MJ/m2a. An expert team provided information on the quantities of building materials and elements required for the construction, established a BIM model and quantified the operational energy demand. Results: The greenhouse gas emissions and environmental impacts of the building were quantified using 17 country-specific national assessment methods and LCA databases. Comparisons of the results are shown on the level of building elements as well as the complete life cycle of the building. Conclusions: The results of these assessments show that the main differences lie in the LCA background data used, the scope of the assessment and the reference study period applied. Despite the variability in the greenhouse gas emissions determined with the 17 national methods, the individual results are relevant in the respective national context of the method, data, tool and benchmark used. It is important that environmental benchmarks correspond to the particular LCA approach and database of a country in which the benchmark is applied. Furthermore, the results imply to include building technologies as their contribution to the overall environmental impacts is not negligible. Grant support: The authors thank the IEA for its organizational support and the funding organizations in the participating countries for

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IOP Conference Series: Materials Science and engineering 2018年第1期307卷

作者： Congqi Li Ruojun Wang Ronggui Liu College of Civil Engineering and Mechanics Jiangsu University Zhenjiang China College of Civil Science and Engineering Yangzhou University Yangzhou China College of Civil and Construction Engineering National Taiwan University of Science and Technology Taipei Taiwan

All articles must contain an abstract. The abstract text should be formatted using 10 point Times or Times New Roman and indented 25 mm from the left margin. Leave 10 mm space after the abstract before you begin the main text of your article, starting on the same page as the abstract. The abstract should give readers concise information about the content of the article and indicate the main results obtained and conclusions drawn. The abstract is not part of the text and should be complete in itself; no table numbers, figure numbers, references or displayed mathematical expressions should be included. It should be suitable for direct inclusion in abstracting services and should not normally exceed 200 words in a single paragraph. Since contemporary information-retrieval systems rely heavily on the content of titles and abstracts to identify relevant articles in literature searches, great care should be taken in constructing both.

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Experimental and theoretical studies of single and double-layer slabs supported on four sides

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AIP Conference Proceedings 2019年第1期2077卷

作者： Dmytro Smorkalov Oleksandr Zhuravskyi Mykhaylo Delyavskyy 1Kyiv National University of Construction and Architecture Department of reinforced concrete and stone structures 03680 Povitroflotskyi ave. 31 Kyiv Ukraine 2University of Technology and Life Sciences Faculty of Civil Engineering Architecture and Environmental Engineering ul. prof. S. Kaliskiego 7 85-768 Bydgoszcz Poland

Presented method and results of experimental research of deflection of one-layer and two-layer slabs influenced by short-term lateral load. Proposed method of calculation based on the limit equilibrium method, calculation of slab deflections values by LIRA-CAD bundled software. The comparison of experimental and theoretical results of the calculation of deflections slabs was performed.

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Correction: Regulation of nitrogen dynamics at the sediment-water interface during HAB degradation and subsequent reoccurrence

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RSC advances 2020年第31期10卷 18038页

作者： Weiping Sima Meijuan Hu Qiang He Yixi Qiu Yitao Lv Lichun Dai Qingwei Shao Tao Zhou Hong Li Manyu Zhou Hainan Ai Hao Zhan Department of Civil Engineering Sichuan University of Science and Engineering Zigong 400045 P. R. China. Key Laboratory of Eco-Environment of Three Gorges Region Ministry of Education Chongqing University Chongqing 400044 P. R. China aihainan@***. Biomass Energy Technology Research Center Biogas Institute of Ministry of Agriculture Chengdu 610041 P. R. China. The Tibet Autonomous Region Housing Urban-rural Development Hall Job Training Center China. Chongqing Haoyang Water Construction Management Co. Ltd. Chongqing 400020 PR China.

[This corrects the article DOI: 10.1039/C9RA10673A.].

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Behavior and characteristics of compacted expansive unsaturated bentonite-sand mixture

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Journal of Rock Mechanics and Geotechnical engineering 2016年第5期8卷 629-639页

作者： Mohammed Y.Fattaha Aysar H.S.Al-Lami Department of Building and Construction Engineering University of TechnologyBaghdadIraq Department of Civil Engineering University of BaghdadBaghdadIraq

Limited studies dealt with the expansive unsaturated soils in the case of large-scale model close to the field conditions and therefore, there is much more room for improvement. In this study, expansive （bentonite–sand （B–S） mixture） and non-expansive （kaolin） soils were tested in different water contents and dry unit weights chosen from the compaction curve to examine the effect of water content change on soil properties （swelling pressure, expansion indices, shear strength （soil cohesion） and soil suction） for the small soil samples. Large-scale model was also used to show the effect of water content change on different relations （swelling and suction with elapsed time）. The study reveals that the initial soil conditions （water content and dry unit weight） affect the soil cohesion, suction and swelling, where all these parameters slightly decrease with the increase in soil water content especially on the wet side of optimum water content. The settlement of each soil at failure increases with the increase in soil degrees of saturation since the matric suction reduces the soil ability to deform. The settlement observed in B–S mixture is higher than that in kaolin due to the effect of higher swelling observed in B–S mixture and the huge amount of water absorbed which transformed the soil to highly compressible soil. The matric suction seems to decrease with elapsed time from top to bottom of tensiometers due to the effect of water flowing from top of the specimen. The tensiometer reading at first of the saturation process is lower than that at later period of saturation （for soil sample B–S3, the tensiometer #1 took 3 d to drop from 93 kPa to 80 kPa at early stage, while the same tensiometer took 2 d to drop from 60 kPa to 20 kPa）.

关键词： Clay Expansive unsaturated soils Swelling Suction

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IMPACTS OF construction RISKS ON COSTS IN LEED-CERTIFIED PROJECTS

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Journal of Green Building 2016年第4期11卷 163-181页

作者： Asli Pelin Gurgun David Arditi Pablo Casals Vilar Department of Civil Engineering Yildiz Technical UniversityDavutpasa Campus34220IstanbulTurkey. Construction Engineering and Management Program Illinois Institute of TechnologyDepartment of CivilArchitectural and Environmental EngineeringAlumni Memorial HallRoom 229ChicagoIL 60616USA. Construction Engineering and Management Program Illinois Institute of TechnologyDepartment of CivilArchitectural and Environmental Engineering IL60616USA

construction according to green principles rather than traditional methods poses a new set of risks to project *** risks should be appropriately identified and managed in order to prevent cost *** study aims to identify construction risks and their cost impacts in LEED-certified *** this purpose,thirteen risks were identified based on a literature survey and were categorized under four groups of issues:(i)consultant,contractor and subcon-tractor,(ii)material,product and process,(iii)legal,regulatory and contractual,and(iv)financial and economic.A survey was then administered to green build-ing design and construction practitioners in the *** assess the likelihood of occurrence of these risks and their respective impacts on project *** to the survey results,the risks associated with consultant,contractor and subcon-tractor issues have the highest expected impact on *** top five risk factors were determined as(1)contractors and subcontractors agreeing to standards that are not within their expertise and competence,(2)high cost of certification,(3)lack of expertise in new products/technologies,(4)doubts about the long-term viability and performance of new and untested products,materials and tech-nologies,and(5)inadequate definition of project parties’contractual roles and *** the cost impact of risks is of great value to owners and designers and *** the risks associated with LEED-certified projects and their cost impacts can be of benefit to all practitioners.

关键词： green construction LEED certification risk cost green risk management

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Blasting cushion pad of reducing vibration start a new era of decreasing disaster in civil and mining engineering explosion with micro-damage

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IOP Conference Series: Earth and Environmental Science 2019年第1期351卷

作者： X Cheng H G LI R Z Han X D Meng J R Zhou L H Duan Y Peng J Zheng L Fu X Lu H B Zhang Y P Liu C H Huang Civil and Environment Engineering School University of Science and Technology Beijing State Key Laboratory of High-Efficient Mining and Safety of Metal Mines (University of Science and Technology Beijing) Ministry of Education Beijing China Nanjing Duble Metal Equipment Engineering Co. Ltd Nanjing China Guangdong Zhongren Group Construction Co. Ltd. Guangzhou China Beijing Zhongkeli Blasting Technique Engineering Co. Ltd. Beijing China Jiangxi Science & Technology Research Centre for Work Safety Jiangxi Nanchang China School of Information Engineering Nanjing Audit University Nanjing China Chongqing Urban Construction Holding (Group) Co. Ltd. Chongqing China State Key Laboratory for Deep Geotechnical Mechanics and Underground Engineering China University of Mining and Technology Xuzhou Jiangsu China Xinjiang Coal Sciences Research Institute Urumqi Xinjiang China Xinjiang Coal Design Research Institute Ltd. Company Urumqi Xinjiang China Jiangxi Provincial Engineering Research Center of the Special Reinforcement and Safety Monitoring Technology in Hydraulic & Civil Engineering Nanchang Institute of Technology Nanchang China

Millisecond delayed blasting has been widely used in reducing vibration of engineering blasting practice before. Pre-splitting blasting has been widely used in reducing vibration of rock slope excavation by blasting up to now. There was still damage to surrounding rock by millisecond delayed blasting and pre-split blasting even smooth blasting. The recurrent blasting vibration will produce cumulative damage to surrounding rock mass of underground and rock slope engineering, even induce rock mass fracture, collapse, roof fall or instability landslide . The damage area is much larger than the blasting excavation area, so rock mass would be damaged several times and result in accumulative damage. Not only the disturbance of single blasting on the surrounding rock should be controlled during blasting construction of anchorage roadway or tunnel, but the emphasis should be put on the accumulative vibration effect of surrounding rock induced by frequent circle short-distance blasting and the corresponding control measures should be taken. This paper introduces a cushion pad which has simple structure and is easy used in blasting engineering. This device can not only avoid large amount of cracks on the rock slope and cumulative damage to surrounding rock mass and rock mass of engineering to instability induced after blasting, but also cushion and hold up at large extent heavy detonation shock after blasting. It is first used in Panzhihua Xujiagou iron open pit, Huayinshan coal mine with gas in SiChuan province, Miaowei hydropower station in Yunnan province and Minshui tunnel blasting engineering in Xin-Fen highway in Hebei-Shanxi province. It effectively cushion the heavy detonation shock from explosion avoiding the damage surface of surrounding rock and accumulated damage of rock, thus improve stability of rock mass and save a large amount of support costs. The vibration velocity with cushion is 50% less than with pre-splitting blasting, even less than the threshold of bla

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Behaviour of machine foundations resting on saturated sand granular tire rubber mixtures

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IOP Conference Series: Materials Science and engineering 2018年第1期433卷

作者： F H. Rahil S A. Abd-Almuniem Assist Professor Building and Construction Engineering Department University of Technology Baghdad Iraq M.Sc. Geotechnical Engineering Civil Engineering Department University of Technology Baghdad Iraq.

This study aims to investigate the behaviours of machine foundations resting on sand granular tire rubber mixtures after saturation. Kerbala sand with two relative densities, 35% and 60%, and granular rubber of sizes 0.07 to 3 mm, resulting from hashing scrap tires into small pieces, were used. A harmonic vertical mode of vibration was applied using a mechanical oscillator fixed on a square steel footing (200 × 200 × 20 mm). The footing was rested on sand inside a steel box of size 1200 × 1200 × 900 mm. Nine model tests were carried out on saturated sand to study the effects of 0, 8, and 12% mix ratios and 0.5 B and 1 B mixing depth for the two relative densities and two frequencies (69 Hz and 80 Hz) in terms of displacement amplitude, settlement, and excess pore water pressure generation in soil. The same number of models were tested for a comparison of dry sand under the effects of the same parameters. The results showed that, in general, the displacement amplitude decreased and the settlement increased for saturated sand compared to dry sand under the same conditions. Mixing granulated tire rubber with saturated sand decreased the displacement amplitude, settlement, and excess pore water pressure; the range of percentages of reduction were from 19% to 73%, 40% to 70%, and 24% to 60% respectively.

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