http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
고속도로 하부 횡단 배수시설로 사용되는 파형 플래스틱 관의 덮개 요건
Kang, Junsuk,James S. Davidson,Lim, Jeong-Hyeon,Kang, Young Jong 한국복합신소재구조학회 2013 복합신소재구조학회논문집 Vol.4 No.1
This project investigated the use of two types of thermoplastic pipes, High-Density Polyethylene (HDPE) and Poly-vinyl Chloride (PVC), as cross-drains under highways. Pipes ranging from 0.3 m (12 in.) to 1.5 m (60 in.) in diameter were evaluated under deep fills, minimum cover, and construction loads. In addition to a comprehensive literature review, an analytical study into the allowable fill heights for thermoplastic pipes and a field study to observe the installation and performance of the pipe in service conditions were conducted. Based on the study findings, recommendations regarding how and when thermoplastic pipe should be installed are provided.
Ultimate strength of horizontally curved steel I-girders with equal end moments
Lee, Keesei,Davidson, James S.,Choi, Junho,Kang, Youngjong Elsevier 2017 ENGINEERING STRUCTURES Vol.153 No.-
<P><B>Abstract</B></P> <P>Even under gravitational loading alone, horizontally curved girders experience not only bending moment but also torsional moment. The torsional moment acting on open sections simultaneously produces shear and normal stress due to pure and warping torsion respectively. Consequently, bending moment, pure torsion and warping torsion are coupled, which results in a very complicated stress state that makes it difficult to calculate the ultimate strength of horizontally curved members. This study revealed that the initial curvature can reduce the ultimate strength of horizontally curved members by up to 50%. Although current design specifications such as the AASHTO LRFD Bridge Design Specifications, suggest some alternatives, the exact behavior of a curved member cannot be considered well with those provisions. While it is true that the one-third rule is convenient to apply and gives good results, there is no strength equation for curved members. In order to derive an adequate strength equation for curved members, this research suggests a new concept of ultimate state. Finite element analysis using ABAQUS is used to consider the effects of sectional rigidities for bending, pure torsion and non-uniform torsion separately. Finally, an ultimate strength equation is suggested for simply supported curved girders that are subjected to equal end moments.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Bending-torsion interaction can affect the strength of horizontally curved member. </LI> <LI> This paper introduces a new concept, termed “Lateral Torsional Vertical Behavior”. </LI> <LI> Three main factors that affect ultimate strength for curved members are demonstrated. </LI> <LI> A strength equation for curved I-girders subjected to pure moment is suggested. </LI> </UL> </P>
고속도로 하부 횡단 배수시설로 사용되는 파형 플래스틱 관의 덮개 요건
강준석 ( Jun Suk Kang ),( James S. Davidson ),임정현 ( Jeong Hyeon Lim ),강영종 ( Young Jong Kang ) 한국복합신소재구조학회 2013 복합신소재구조학회논문집 Vol.4 No.1
This project investigated the use of two types of thermoplastic pipes, High-Density Polyethylene (HDPE) and Poly-vinyl Chloride (PVC), as cross-drains under highways. Pipes ranging from 0.3 m (12 in.) to 1.5 m (60 in.) in diameter were evaluated under deep fills, minimum cover, and construction equipment loads. In addition to a comprehensive literature review, an analytical study into the allowable fill heights for thermoplastic pipes was conducted. Based on the study findings, recommendations regarding how and when thermoplastic pipe should be installed are provided.
Cover Requirements for Corrugated HDPE and PVC Pipes Used for Cross-drains in Highway Construction
강준석,임정현,강영종,Kang, Junsuk,Davidson, James S.,Lim, Jeong-Hyeon,Kang, Young Jong Korean Society for Advanced Composite Structures 2013 복합신소재학회논문집 Vol.4 No.1
This project investigated the use of two types of thermoplastic pipes, High-Density Polyethylene (HDPE) and Poly-vinyl Chloride (PVC), as cross-drains under highways. Pipes ranging from 0.3 m (12 in.) to 1.5 m (60 in.) in diameter were evaluated under deep fills, minimum cover, and construction loads. In addition to a comprehensive literature review, an analytical study into the allowable fill heights for thermoplastic pipes and a field study to observe the installation and performance of the pipe in service conditions were conducted. Based on the study findings, recommendations regarding how and when thermoplastic pipe should be installed are provided.
Mehran Jalali Moghadam,Justin D. Marshall,James S. Davidson 한국강구조학회 2023 International Journal of Steel Structures Vol.23 No.2
Although the nominal strength of modern steel bridges that involve increasingly slender elements has been well defined through extensive research and testing, fatigue concerns have not been thoroughly investigated. The out-of-plane displacements of slender webs result in secondary bending stresses at the web boundaries connections, i.e., flange and stiffeners. The so-called “web breathing” phenomenon potentially leads to fatigue crack initiation at the web boundary connections and has been studied for straight girders. Curved steel girders experience large deflection and rotations during construction and service that can intensify the web breathing effect. In addition, the curvature-induced lateral forces pushing and pulling slender curved webs develop mechanisms that can lead to critical web boundary stresses that do not typically occur in straight bridges. This paper aims to define the slender web behavior of composite curved steel bridges essential for the fatigue limit state. It focuses on capturing the distortion-induced web stresses from the construction stage through service using 3D finite element analyses. An advanced technique was applied to simulate the non-composite and composite stages to quantify the continuous web stress development due to geometric nonlinearities. Three different web panels under high shear, high moment, and high shear-moment combination were studied. The stress ranges due to the AASHTO fatigue truck is presented for composite bridges with varying curvature radii. The mechanism involved in curved bridges is defined and the stress magnitudes are compared to that of equivalent straight bridges to understand the role of curvature in intensifying the critical fatigue stress ranges.