• Title/Summary/Keyword: Civil Engineer

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Prediction of seismic cracking capacity of glazing systems

  • O'Brien, William C. Jr.;Memari, Ali M.;Eeri, M.
    • Earthquakes and Structures
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    • v.8 no.1
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    • pp.101-132
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    • 2015
  • This research formulates a closed-form equation to predict a glass panel cracking failure drift for several curtain wall and storefront systems. An evaluation of the ASCE 7-10 equation for Dclear, which is the drift corresponding to glass-to-frame contact, shows that the kinematic modeling assumed for formulation of the equation is sound. The equation proposed in this paper builds on the ASCE equation and offers a revision of that equation to predict drift corresponding to cracking failure by considering glazing characteristics such as glass type, glass panel configuration, and system type. The formulation of the proposed equation and corresponding analyses with the ASCE equation is based on compiled experimental data of twenty-two different glass systems configurations tested over the past decade. A final comparative analysis between the ASCE equation and the proposed equation shows that the latter can predict the drift corresponding to glass cracking failure more accurately.

Numerical model for local corrosion of steel reinforcement in reinforced concrete structure

  • Chen, Xuandong;Zhang, Qing;Chen, Ping;Liang, Qiuqun
    • Computers and Concrete
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    • v.27 no.4
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    • pp.385-393
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    • 2021
  • Reinforcement corrosion is the main cause of the durability failure of reinforced concrete (RC) structure. In this paper, a three-dimensional (3D) numerical model of macro-cell corrosion is established to reveal the corrosion mechanisms of steel reinforcement in RC structure. Modified Direct Iteration Method (MDIM) is employed to solve the system of partial differential equations for reinforcement corrosion. Through the sensitivity analysis of electrochemical parameters, it is found that the average corrosion current density is more sensitive to the change of cathodic Tafel slope and anodic equilibrium potential, compared with the other electrochemical parameters. Furthermore, both the anode-to-cathode (A/C) ratio and the anodic length have significant influences on the average corrosion current density, especially when A/C ratio is less than 0.5 and anodic length is less than 35 mm. More importantly, it is demonstrated that the corrosion rate of semi-circumferential corrosion is much larger than that of circumferential corrosion for the same A/C ratio value. The simulation results can give a unique insight into understanding the detailed electrochemical corrosion processes of steel reinforcement in RC structure for application in service life prediction of RC structures in actual civil engineer.

A Study of the Tendon Profile of a PSC Continuous Beam Able to Resist the Negative Bending Moment of Continuous Intergirders (거더 연속부의 부모멘트 제어에 효과적인 PSC 연속보의 텐던 배치에 관한 연구)

  • Kim, Eui Hun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.41 no.6
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    • pp.617-625
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    • 2021
  • The problems associated with the continuous method of a domestically improved prestressed concrete (PSC) girder and the bending moment of a continuous tendon were studied. Based on the results, a continuous tendon model was proposed that can resist the negative bending moment of an intergirder. This model lowers the anchorage of the continuous tendon as far as possible under the girder, and extends the tendon section arranged under the girder. This method reduces the PS's bending moment in the middle of the span, but maximizes it in the intergirder. This continuous tendon model can offer a suitable method for continuity before manufacturing a composite, which requires a higher design bending moment in the intergirder than in the middle of the span.

A STUDY ON DURATION ESTIMATE METHOD USING STOCHASTIC MODEL IN THE BIM ENVIRONMENT

  • Jae H. Park;Seok H. Yun;Joon H. Paek
    • International conference on construction engineering and project management
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    • 2009.05a
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    • pp.1209-1215
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    • 2009
  • Recently, Construction Projects are being much bigger and more complex. So the importance of Construction Planning and Management is increasing and increasing because of the Construction Projects is involved in a variety of construction-related subjects. Competitive of the Construction Industry decided Cost, Construction Duration and Productivity. But they were just focused on Cost Saving instead of Construction Duration and Productivity. However, they have to finish construction projects using minimum cost and duration with quality and function of required level for successful Construction projects. Thus, current high exchange rate and high period, it is clear to decrease construction cost and to do economic construction in huge Construction Projects and it means more advanced Construction Schedule Management needs for economic construction. But Construction Scheduling Planning, basic of Construction Schedule Management, adjusted contract period without Pre-Planning, just depending on experience and ability of Construction Engineer. Because of that, this study suggests new Duration Estimate Method using Stochastic Model in BIM Environment for advanced Construction Schedule Management. Existing Duration Estimate Methods are just modified wrong points of them or analyzed effective factors of construction schedule. However, New Duration Estimate Method is just consists of Stochastic Model and BIM Environment without existing Duration Estimate Methods. So, new method has creativity and specialty. After this research, it would be a great model in construction industry field.

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Analysis of Federal Expenses to Restore, Repair, Reconstruct, or Replace Disaster Damaged Roads and Bridges in the U.S.

  • Bhattacharyya, Arkaprabha;Hastak, Makarand
    • International conference on construction engineering and project management
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    • 2022.06a
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    • pp.929-936
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    • 2022
  • In the U.S., the state, local, tribe, and territorial governments seek funding from the federal government through the Public Assistance program to carry out these recovery works. In this paper historic public assistance data between 1998 and 2021 have been analyzed to derive several insights such as: types of disasters causing the most damage, states requiring more support, net present value of the federal expense etc. This paper has found that the states requiring more support from the federal government are not always the states suffering the maximum losses from the disasters. It has also found that the net present value of the federal expense between 1998 and 2020 to restore, repair, reconstruct, or replace disaster damaged roads and bridges across the U.S. is $15 billion in 2021 values. Moreover, this paper has tested the correlation between the states' public assistance funds requirements and the existing condition and performance of roads and bridges as revealed by the American Society of Civil Engineer's infrastructure grade card. It has found a weak correlation between these two. The outcomes of this paper can be used by the decision makers to analyze the viability of any possible alternative to the exiting public assistance program. The insights can also help in better decision making in pre-disaster preparation and post-disaster funds allocation.

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New methodology of backbone curve for RC perforated shear walls

  • Yang, Jing-Shyang;Cheng, Franklin Y.
    • Structural Engineering and Mechanics
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    • v.14 no.3
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    • pp.365-380
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    • 2002
  • Following a series of experiments on isolated low-rise RC shear walls with openings, a theoretical study on the backbone curve of a perforated shear wall shows that there are some important observations from experimental results that make clear a semi-empirical formula of the backbone curve of a perforated wall. Critical shear zones can be depicted from the configuration of shear walls with openings. Different factors, including the size and location of shear wall openings, the wall's height/width ratio, horizontal and vertical steel bar ratios, and location and amount of diagonal steel bars are involved in the derivation of the backbone curve. Bending and shear effects are also considered in the paper. In addition, a comparison of load and displacement for solid and perforated shear walls is discussed. Generally, the comparison between experimental curves and computed backbone curves is favorable.

Analysis on the submittal process for a small local environmental construction company: a case study (지역 소규모 환경건설회사의 제출/승인 절차 분석에 관한 사례 연구)

  • Lee, Do Gyun
    • Journal of Urban Science
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    • v.6 no.2
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    • pp.73-80
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    • 2017
  • A submittal, as a part of three main project management processes: production control, submittals and change orders, is the transmission of information from the subcontractor to the general contractor to the owner, architect, and structural engineer, for review and approval. The purpose of the submittal process is for submittals to be approved in order to start construction. This benefits the contractor by ensuring that the finished project will meet the expectations of the owner. This paper analyzed a case study regarding the submittal process for the local-based environmental construction company, which typically works as a subcontractor and may hire other subcontractors for additional work when applicable. The aim of this study was to roughly evaluate a project management process and understand the submittal process through the study of a case involving the local company.

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Application of Long Gauge Fiber Optic Sensors to Construction Engineering Structures (장대 광변형 센서의 건설 구조물 적용)

  • 로드테니슨;안명운;김상환
    • Proceedings of the Korean Geotechical Society Conference
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    • 2001.10c
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    • pp.61-78
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    • 2001
  • Various kind of fiber optic gauge sensors are available that can be bonded to civil engineering structures such as bridges, dams, tunnels and pipelines. A new fiber optic long gauge has significant advantages over other fiber optic sensors. These gauges can vary in length from less than 10 cm up to 30 m and provide the structural engineer with accurate measurements of displacement. These displacements can be converted to strains by dividing the measurement by the long gauge length. Using new optical technology, the long gauge instrument developed by FOX-TEK can choose max. 30 meters of gauge length so as to measure the very early stress/strain correlation curve. And this gauge length to be extended up to 100 meter in 2002.

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A study on the problem and Counter measure of plant Construction project. -Based on tile work of both civil engineering and steel structure in the plant construction project of On-San Refinery- (PLANT 건설공사의 문제점과 대책에 관한 고찰 (온산동련소 건설의 토건공사및 철골공사 사례를 중심으로))

  • 유광수
    • Journal of the Korean Professional Engineers Association
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    • v.16 no.1
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    • pp.13-19
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    • 1983
  • As one of staff members participated in the full course of the plant construction project of On-san Refinery to its successful completion. I had my past expierence that the plant construction project was so complicated, and a Long period required, and thus there were so money problems to be solved. Among the problem, I mainly noticed that the following listed points were solved and improved. 1. Each drawing should be in every accuracy possible. 2. Contract should be specified in every detail possible. 3. All invoiced prices of breack down list should be coped with the current market prices. 4. All execution of work should be in the most accuracy. A. Planing execution of work. B. Coordination with supervisor group. C. Economical method for execution of work. D. Safety control. 3, Calculation work field should be established seperately 6. Each staff members should be work at the best of his pride.

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Production Liability Law and Method of Protection and Defence (제조물책임법 (PL법)의 변화와 대처방안)

  • 이상복
    • Journal of the Korean Professional Engineers Association
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    • v.30 no.6
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    • pp.153-163
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    • 1997
  • In this paper, we explain Production Liability(PL) law and research method of protection and defence of PL law. In introduction, we give some examples of PL law In main issue, we explain more detail PL law. We survey several country PL law, specially U.S.A., EU, Japan whose are deeply related with us as important export country We discuss our country PL status, our country don't legislate PL law until now We have consumer protection law(소비자보호법) which is weaker than PL law but stronger than civil law(민법), We believe that PL law will be legislated within not long time. At last we discuss protection and defence of PL law inside of company and outside of company as PL insurance.

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