scholarly journals Study on Asymmetric Failure and Control Measures of Lining in Deep Large Section Chamber

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4075
Author(s):  
Yubing Huang ◽  
Bei Jiang ◽  
Yukun Ma ◽  
Huayong Wei ◽  
Jincheng Zang ◽  
...  
Keyword(s):  
Bending Moment ◽  
Control Measures ◽  
Large Section ◽  
Maximum Displacement ◽  
Change Rate ◽  
Evaluation Indexes ◽  
Section Size ◽  
Asymmetric Load ◽  
Under Construction ◽  
Pump House

Lining is often used as the last line of defense in deep large section chamber. Under the asymmetric load, it is easy to damage, resulting in the overall repair of the chamber. Aiming at this problem, taking the pump house in Wanfu Coal Mine under construction in China as an engineering example, we analyzed the asymmetric failure of pump house lining caused by construction disturbance, established the lining mechanical model and quantitative evaluation indexes, such as bending moment change rate, bending moment balance rate, displacement change rate and displacement balance rate, studied the influence mechanism of asymmetrical coefficient, section size and lining thickness on the mechanical behavior of lining, and proposed the control measures of deep large section chamber with the core of “strengthening asymmetric support, reducing section size and improving lining strength”. The field monitoring shows that the asymmetric deformation of the pump house is effectively controlled, and the maximum displacement is only 7.3 mm, which ensures the long-term stability of the chamber.

scholarly journals Fire Hazard Assessment During Construction of A Mixed-Use Development Project In Kuala Lumpur

2018 ◽  
Vol 7 (3.9) ◽  
pp. 5
Author(s):  
Zaamuddin Zakaria ◽  
Syuhaida Ismail ◽  
Wan Nurul Mardiah Wan Mohd. Rani ◽  
Rohayah Che Amat ◽  
Mohammad Hussaini Wahab
Keyword(s):  
Fire Hazard ◽  
Development Project ◽  
Hazard Identification ◽  
Control Measures ◽  
Primary Data ◽  
Risk Level ◽  
Kuala Lumpur ◽  
Safety Control ◽  
Mixed Use ◽  
Under Construction

Construction by nature is inherently dangerous, with a high degree of hazard and risk. Serious fire has occurred in building under construction, which will not delay their completion dates and loss of life, but also result in serious monetary losses. The objectives of this paper are to investigate the causes of fire hazard during the construction phase; assess the risk level arising from the fire hazard during the construction phase; and tpropose safety control measures of fire hazard during the construction phase. Primary data is obtained from the respondents of a mixed use development project in Kuala Lumpur via questionnaire surveys. The data is analysed via Statistical Package for the Social Science (SPSS) and Hazard Identification, Risk Assessment and Risk Control (HIRARC). The findings show that the most important causes of fire hazard of a mixed-use development project are related to workers site activities. Meanwhile, HIRARC identifies that fire hazard from hot works and use electrical tools are the most important risks. Lastly, safety control measures were proposed to control the identified fire hazard by improving the operating procedure of hot works and use of electrical tools as well as implementing good housekeeping practices and inspection at the workplace.  

scholarly journals Quality of Community-based Care Services in Korea

2020 ◽  
Author(s):  
Kichan Yoon ◽  
Insoo Lee ◽  
Youn-Tae Lee ◽  
Munjae Lee
Keyword(s):  
Social Services ◽  
User Satisfaction ◽  
Community Care ◽  
Care Service ◽  
Secondary Data ◽  
Service Evaluation ◽  
Change Rate ◽  
Evaluation Indexes ◽  
Care Services

Abstract Background: Aging societies are increasing the need for care services. In order to solve the problem of care, we suggest community care, and through this, we will provide medical services that meet individual needs. Korea provides care services in advance of the community care project and implements quality control to improve the quality of these social services. Therefore, this study aims is to intend to compare and analyze the factors affecting user satisfaction in care services in both 2013 and 2016.Methods: We used quantified secondary data based on social services performed analysis reports. Based on the evaluation indexes for care service in 2013 and 2016, we used commonly used indexes for analysis.Results: As a result, there was a difference between care services quality evaluation (QE) indexes by profit type, and care services evaluation indexes had an effect on user satisfaction. In addition, the change rate in the care service evaluation scores affects the change rate in user satisfaction.Conclusions: Therefore, in order to increase satisfaction with care service, evaluation indexes by service type should be diversified and differentiated. In addition, it should be composed of field evaluations related to user satisfaction to provide care services appropriate for local characteristics.

scholarly journals Research on Mechanisms and Control Measures of Surrounding Rock Disaster in Large Section Roadway with Top Coal under the Influence of Tectonic Stress

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Yang Yu ◽  
Jianfei Lu ◽  
Dingchao Chen ◽  
Yuxin Pan ◽  
Xiangqian Zhao ◽  
...  
Keyword(s):  
Damage Mechanics ◽  
Tectonic Stress ◽  
Surrounding Rock ◽  
Control Measures ◽  
Shanxi Province ◽  
Stress Effect ◽  
Large Section ◽  
Thick Coal Seam ◽  
Surrounding Rock Control ◽  
Seam Mining

Based on the research background of large section roadway with top coal (LSRTC) in thick coal seam mining in Wangzhuang Coal Mine, Shanxi Province, China, catastrophe characteristics of the surrounding rock of the LSRTC were investigated and summarized. Based on the principle of damage mechanics, the critical size discriminant of the LSRTC was deduced, and the induction mechanism of section size effect and tectonic stress effect on the roadway surrounding rock disaster was revealed. Accordingly, the roadway surrounding rock control principle with the basic idea of “stabilizing and controlling top coal, reconstructing the coal wall, and limiting floor heave” was put forward, and the roadway surrounding rock stability control countermeasures with the core technology of “strong pressure support for roof + grouting reinforcement for two sides + bolt barrier for floor angle” were developed, which solved the surrounding rock control problem of the LSRTC under the action of tectonic stress and provided a useful reference for the difficult problem of roadway surrounding rock control under similar conditions.

scholarly journals Study on Safety Benchmark Value of Monitoring and Early Warning for Large Section Highway Tunnels

2019 ◽  
Vol 136 ◽  
pp. 04024
Author(s):  
Yuwen Wang ◽  
Xiang Yang Cui ◽  
Hongyan Guo ◽  
Ke Li
Keyword(s):  
Side Wall ◽  
Construction Method ◽  
Surrounding Rock ◽  
Large Section ◽  
Deformation Law ◽  
Initial Support ◽  
Under Construction ◽  
Monitoring And Measurement ◽  
Ultimate Displacement ◽  
Wall Method

Taking several tunnels under construction of a highway as the research object, the ultimate displacement of four buried depth sections of 0-50, 50-100, 100-300, 300-500 m in the surrounding rock of grade III, IV and V is numerically simulated by three-step and seven-step excavation method, middle-wall method, cross-middle-wall method and double-side-wall guide pit method for initial support of large-section highway tunnels. Through analysis, the deformation law of tunnel surrounding rock is obtained: under the same buried depth, the displacement ultimate displacement of the two-sided guide pit method and the cross-middle-wall method is the largest, the middle-wall method is the second, and the three-step seven-step excavation method is the smallest. Through the analysis and collation of the measured data obtained by monitoring and measurement of each construction method in the construction site, the surrounding rock deformation datum values of large-span and large-section tunnel under each construction method are obtained.

Technology of Joint Support on Large Pump House in HS Soft Rock

2012 ◽  
Vol 446-449 ◽  
pp. 2202-2205
Author(s):  
Xing Lin Wen ◽  
Lin Hai Gao ◽  
Xiu Shan Li ◽  
Zhao Ping Liu
Keyword(s):  
Numerical Simulation ◽  
Soft Rock ◽  
Large Section ◽  
Anchor Bolt ◽  
Pump House

Soft rock; Anchor bolt-net-spray support; Twice support; Large section; Numerical simulation

scholarly journals Small Pilot Tunnel Advance and Step Reverse Expansion in Super-Large-Section Tunnel Excavation

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Bole Sun ◽  
Xiaorong Tang ◽  
Yongyi He ◽  
Mingnian Wang
Keyword(s):  
Production Efficiency ◽  
Expansion Method ◽  
Surrounding Rock ◽  
Construction Technology ◽  
Construction Time ◽  
Engineering Project ◽  
Large Section ◽  
Maximum Displacement ◽  
Tunnel Support ◽  
In Situ Conditions

Collapse of the vault and numerous other safety accidents often occur during the construction process of large-section tunnels. The utilization of a small pilot tunnel and a step reverse expansion construction methodology is proposed based on conventional construction methods to explore safe construction technology. First, a theoretical analysis combined with on-site monitoring parameters was conducted. It showed that the maximum displacement of the tunnel surrounding rock was 0.027 m during the elastic stage and increased to 0.031 m during the strength limit stage. The overall surrounding rock deformation does not have a noticeable impact on tunnel safety. A numerical simulation model of the small pilot tunnel advancement and step reverse expansion method was established. Simulation results showed that the first two excavation steps caused 89.6% of the total overlining strata subsidence, and the use of a small pilot tunnel advancement and step reverse expansion method can enhance the tunnel support. The tunnel surrounding rock was adequately stabilized after using this excavation method and provides the in-situ conditions for expanding the pilot tunnel to the large-section tunnel. The proposed method was adopted in an actual engineering project. It protected the subsequent construction of the main tunnel and decreased construction time, saving construction costs while ensuring safety, reducing construction risks, and improving production efficiency. This research can guide similar tunneling projects.

scholarly journals Effects of pounding on the behavior of reinforced concrete frame structures in seismic zone 2B

2021 ◽  
Author(s):  
Muhammad Hamid ◽  
◽  
Fayyaz Ur Rahman ◽  
Qaisar Ali ◽  
◽  
...  
Keyword(s):  
Structural Damage ◽  
Bending Moment ◽  
Frame Structures ◽  
Seismic Zone ◽  
Structural Members ◽  
Reinforced Concrete Frame ◽  
Ground Acceleration ◽  
Maximum Displacement ◽  
Analysis And Design ◽  
Axial Forces

Pounding between adjacent buildings is a common phenomenon which can be observed during moderate to high ground shakings that can result in structural damage and even loss of life. As this phenomenon is related to the life safety, therefore, it is imperative to consider it in the modelling stage of structural analysis and design. The current study is intended to evaluate, numerically, the effect of pounding phenomenon in RC frame structures. Three dimensional models of two hypothetical buildings are analyzed by subjecting to three ground acceleration histories that are scaled and matched with BCP-SP07 design spectrum. The analysis results such as inter storey drift, maximum displacement, pounding forces and its effects on bending moment, axial forces, shear and torsional forces in structural members are compared. The results show that pounding forces decrease with increase in gap size and are dominant in top five stories with maximum force at the top floor level. Pounding increase displacement up to 2 times and acceleration up to 240 times as compared to without pounding case. Pounding increase the axial forces up to 250 times and bending moment up to 2 time in the beams parallel to colliding forces. Similarly, the shear forces and torsional moments are almost doubled as a result of pounding. Finally, a 20 storey building consists of four blocks separated by 3-inch expansion joints is modelled combinedly in Etabs and analyzed to see the effect of pounding. Based on the results it is concluded that pounding must be considered at modelling stage of the design to account for the forces induced in the structural members.

scholarly journals Quality of Community-based Care Services in Korea

2020 ◽  
Author(s):  
Kichan Yoon ◽  
Insoo Lee ◽  
Youn-Tae Lee ◽  
MUNJAE LEE
Keyword(s):  
Social Services ◽  
User Satisfaction ◽  
Community Care ◽  
Care Service ◽  
Secondary Data ◽  
Service Evaluation ◽  
Change Rate ◽  
Evaluation Indexes ◽  
Care Services

Abstract Background Aging societies are increasing the need for care services. In order to solve the problem of care, we suggest community care, and through this, we will provide medical services that meet individual needs. Korea provides care services in advance of the community care project and implements quality control to improve the quality of these social services. Therefore, this study aims is to intend to compare and analyze the factors affecting user satisfaction in care services in both 2013 and 2016. Methods We used quantified secondary data based on social services performed analysis reports. Based on the evaluation indexes for care service in 2013 and 2016, we used commonly used indexes for analysis. Results As a result, there was a difference between care services quality evaluation (QE) indexes by profit type, and care services evaluation indexes had an effect on user satisfaction. In addition, the change rate in the care service evaluation scores affects the change rate in user satisfaction Conclusions Therefore, in order to increase satisfaction with care service, evaluation indexes by service type should be diversified and differentiated. In addition, it should be composed of field evaluations related to user satisfaction to provide care services appropriate for local characteristics.

Temperature Cracks Controlling Technology for the Mass Concrete in Solid Sections of Lower Pylon Column

2013 ◽  
Vol 467 ◽  
pp. 262-269
Author(s):  
Fu Liang Gao ◽  
Yan Wei Fang
Keyword(s):  
Temperature Control ◽  
Thermal Stresses ◽  
Cooling Water ◽  
Control Measures ◽  
Mass Concrete ◽  
Removal Time ◽  
Control Scheme ◽  
Section Size ◽  
Circulating Cooling Water ◽  
Binder Ratio

According to the case that mass concrete in solid sections of lower pylon column of Jiashao Bridge was easy to crack in construction because of the bigger section size, larger content of cementitious material and lower water binder ratio, the temperature and thermal stresses distribution of mass concrete was simulated and temperature control scheme was adjusted constantly based on the results of field temperature monitoring. Through taking some temperature control measures such as applying circulating cooling water and prolonging the time appropriately, thermal insulation and moisture retention curing, extending the form removal time and controlling the quality of concrete, harmful cracks did not appear in solid sections of lower pylon column of Jiashao Bridge and anticipated temperature control requirements were achieved.

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