조인트 버스팅을 고려한 세그먼트 라이닝 구조해석 및 설계방법

김홍문,김현수,정혁일 사단법인 한국터널지하공간학회 2018 한국터널지하공간학회논문집 Vol.20 No.6

Segment lining applied to the TBM tunnel is mainly made of concrete, and it requires sufficient structural capacity to resist loads received during the construction and also after the completion. When segment lining is design to the Limit State Design, both Ultimate Limit State (ULS) and Service Limit State (SLS) should be met for the possible load cases that covers both permanent and temporary load cases - such as load applied by TBM. When design segment lining, it is important to check structural capacity at the joints as both temporary and permanent loads are always transferred through the segment joints, and sometimes the load applied to the joint is high enough to damage the segment - so called bursting failure. According to the various design guides from UK (PAS 8810, 2016), compression stress at the joint surface can generate bursting failure of the segment. This is normally from the TBM’s jacking force applied at the circumferential joint, and the lining’s hoop thrust generated from the permanent loads applied at the radial joint. Therefore, precast concrete segment lining’s joints shall be designed to have sufficient structural capacity to resist bursting stresses generated by the TBM’s jacking force and by the hoop thrust. In this study, bursting stress at the segment joints are calculated, and the joint’s structural capacity was assessed using Leonhardt (1964) and FEM analysis for three different design cases. For those three analysis cases, hoop thrust at the radial joint was calculated with the application of the most widely used limit state design codes Eurocode and AASHTO LRFD (2017). For the circumferential joints bursting design, an assumed TBM jack force was used with considering of the construction tolerance of the segments and the eccentricity of the jack’s position. The analysis results show reinforcement is needed as joint bursting stresses exceeds the allowable tensile strength of concrete. This highlights that joint bursting check shall be considered as a mandatory design item in the limit state design of the segment lining. 쉴드 TBM터널에 적용되는 세그먼트 라이닝은 주로 콘크리트로 제작되며, 시공 중 및 완공 후 작용 하중에 견딜 수 있는충분한 강도가 요구된다. 한계상태설계법에 의한 세그먼트라이닝 설계는 주로 극한하중상태(ULS) 및 사용하중상태(SLS)에 대하여 검토하며, 상시하중과 임시하중에 대하여 발생 가능한 조합을 구성하여 적용한다. 또한 TBM에 의한 시공을 고려한 한계상태 설정과 구조해석이 필요하며, 특히 세그먼트라이닝은 현장에서 조립되어 원형구조물을 완성하는방식이기 때문에, 콘크리트표면이 접촉하는 조인트가 필수적으로 존재하며 이 조인트를 통해 상당한 크기의 압축응력이전달되므로 조인트에 대한 구조검토가 중요하다. 일반적으로 세그먼트 라이닝의 원주방향 조인트(circumferential joint)와 반경방향 조인트(radial joint)에서의 인장응력에 대하여 FEM모델이나 이론식으로 검토한다. 영국의 설계지침(PAS 8810, 2016)에 의하면, 버스팅을 일으키는 조인트에서의 압축응력은 원주방향 조인트(circumferential joint)에잭 추력을 가하는 경우뿐만 아니라 반경방향 조인트(radial joint)에 축력이 전달되는 경우에도 발생하므로 버스팅 응력을 검토하여 세그먼트의 인장강도와 비교하여 필요할 경우 보강을 하여야 한다. 본 연구에서는 대표적인 한계상태설계코드인 EURO CODE와 AASHTO LRFD (2017)의 하중조건을 적용하여 조인트 응력을 비교 분석하였고, FEM해석을 통하여 버스팅(bursting)을 유발하는 조인트응력을 평가하고 발생경향을 이론식과 비교 분석하였다. 분석결과, 조인트 응력이 콘크리트의 허용 인장강도를 초과하는 경우가 발생하여 보강이 필요한 것으로 검토되었다. 따라서 조인트 버스팅 검토는 세그먼트라이닝 한계상태설계 시 설계항목으로 비중 있게 고려할 필요가 있다.

역학적-경험적 콘크리트 포장 줄눈간격 설계방법 개발

박주영,홍동성,임진선,정진훈 한국도로학회 2011 한국도로학회논문집 Vol.13 No.4

온도와 습도 변화에 의해 수축될 경우 콘크리트 포장 슬래브에는 인장응력이 생기고 이로 인해 무작위 균열이 발생한다. 일정한 간격으로 줄눈을 설치하고 균열을 유도함으로써 슬래브에 발생하는 인장응력을 줄이고 무작위 균열을 최소화할 수 있다. 줄눈간격이 너무 넓으면 무작위 균열, 줄눈부 파손, 하중전달률 저하가 일어나고, 반대로 줄눈간격이 너무 좁으면 공사비 증가와 승차감 저하가 유발된다. 본 연구에서는 콘크리트 포장의 역학적-경험적 줄눈간격 설계방법을 개발하였다. 이를 위하여 우수한 공용성을 보이는 콘크리트 포장 구간 중 구조적 및 환경적으로 가장 취약한 구간을 찾고 그 구간에 대한 유한요소해석으로 설계기준강도를 결정하였다. 기존 연구결과를 참고하여 하중전달률이 급격히 낮아질 때의 줄눈폭을 허용줄눈폭으로 결정하였다. 유한요소해석으로 계산된 설계대상구간의 최대인장응력이 설계기준강도를 초과하지 않는 최대줄눈간격을 찾아냈다. 그리고 이 줄눈간격으로 예측된 최대줄눈폭을 허용줄눈폭과 비교하였다. 본 연구에서 개발된 방법을 설계 중인 함양-울산 고속도로의 두 공구에 적용해 보았다. 기존보다 넓은 8.0m의 줄눈간격으로 시험시공된 구간과 동일한 줄눈간격이 본 연구의 설계방법으로 계산되었다. 공용 6년 후 측정된 시험시공 구간의 매우 낮은 균열률로 본 연구에서 개발된 설계방법이 검증되었다. Tensile stress occurs and random crack develops in concrete pavement slab when it contracts by variation of temperature and humidity. The tensile stress decreases and the random crack is minimized by sawcutting the slab and inducing the crack with regular spacing. The random crack, joint damage, decrease of load transfer efficiency are caused by too wide joint spacing while too narrow joint spacing leads to increase of construction cost and decrease of comfort. A mechanistic-empirical joint spacing design method for the concrete pavement was developed in this study. Structurally and environmentally weakest sections were found among the sections showing good performance, and design strengths were determined by finite element analysis on the sections. The joint width for which the load transfer efficiency is suddenly lowered was determined as allowable joint with referring to existing research results. The maximum joint spacing for which the maximum tensile stress calculated by the finite element analysis did not exceed the design strength were found. And the maximum joint width expected by the maximum joint spacing were compared to the allowable joint width. The new method developed in this study was applied to two zones of Hamyang-Woolsan Expressway being designed. The same joint spacing as a test section constructed by 8.0m of joint spacing wider than usual was calculated by the design method. Very low cracking measured at 6 years after opening of the test section verified the design method developed in this study.

사례 분석을 통한 복합말뚝 이음위치의 설계 기준식 개선 연구

황의성 한국지반환경공학회 2019 한국지반환경공학회논문집 Vol.20 No.3

Composite pile, which is composed of the steel pipe pile in which the large horizontal force acts and the PHC pile in which the small horizontal force acts by a special connecting devices, is being commercialized as a base material for civil engineering structures. The core of such a composite pile can be said to be a design criterion for estimating the joint position and stability of the connection device between steel pipe pile and PHC pile. In Korea, there is no precise specification for the location of composite pile joints. In the LH Design Department (Korea Land & Housing Corporation, 2009), “Application of composite pile design and review of design book marking” was made with reference to Road Design Practice Volume 3 (Korea Expressway Corporation, 2001). this is used as a basis of the design of the composite pile. It can not be regarded as a section change of the composite pile, so it has a limitation in application. Therefore, In this study, we propose a design criterion for the location of the section of the composite pile (joint of steel pipe pile and PHC pile) and evaluate the stability and economical efficiency of it by using experimental method and analytical method. Analysis of composite pile design data installed in 79 domestic bridges abutment showed that the stresses, bending moments, and displacements acting on the pile body and connection of the pile were analyzed. Through the redesign process, it was confirmed that the stresses generated in the connecting device occur within the allowable stress values of the connecting device and the PHC pile. In conclusion, the design proposal of composite pile joint location through empirical case study in this study is an improved design method considering both stability and economical efficiency in designing composite pile. 복합말뚝(Composite Pile)이란, 수평력이 크게 작용하는 구간에는 강관말뚝, 작게 작용하는 구간에는 PHC말뚝을 특수한 연결 장치로 결합한 말뚝으로서 토목 구조물의 기초 재료로써 상용화되는 추세에 있다. 이러한 복합말뚝의 핵심은 강관말뚝과 PHC말뚝을 연결하는 연결 장치의 안정성과, 이음 위치를 산정하는 설계기준이라고 할 수 있는데 국내에서는 복합말뚝 이음부 위치에 대한 정확한 시방규정이 없어서, LH 설계처(한국토지주택공사, 2009)에서는 도로설계요령 제3권(한국도로공사, 2001)을 참고하여 작성한 “복합말뚝 설계적용 및 설계도서 표기 방안 검토”를 복합말뚝 설계의 기준으로 사용해 오고 있지만 복합말뚝의 단면변화라고 볼 수 없어 적용에 한계성을 가지고 있는 실정이다. 이에 따라 본 연구에서는 복합말뚝의 단면 변화부(강관말뚝과 PHC말뚝의 이음부) 위치에 대한 설계기준을 제안하고 이에 대한 안정성 및 경제성을 검토하고자 실험적인 방법과 해석적인 방법을 이용하여 연결장치에 대한 안정성을 검증하였으며, 국내 교량공사 교대 79개소에 시공된 복합말뚝 설계자료를 분석하여 말뚝 본체 및 이음부에 작용하는 응력, 휨모멘트, 변위 등의 경향성을 파악하였고, 개선식이 적용된 재설계 과정을 통해 이음부에서 발생한 응력들이 연결장치와 PHC말뚝의 허용응력 수치 내로 발생하는 것을 확인하였다. 결론적으로 사례분석을 통한 복합말뚝 이음위치의 설계 제안식은 복합말뚝을 설계함에 있어서 안정성과 경제성을 모두 고려한 개선된 설계기법임을 알 수 있었다.

조인트 DB와 다분야 구속 조건 최적설계를 이용한 차체 설계 프로세스 개발

박현정(Hyun-Jung Park),최연욱(Yeon-wook Choi),허승진(Seung-Jin Heo),이경원(Kyungwon Lee),김정호(Jung-Ho Kim),이창건(Changkun Lee),김용석(Yongsuk Kim) 한국자동차공학회 2014 한국자동차공학회 학술대회 및 전시회 Vol.2014 No.11

To achieve effectiveness and optimized design for light weight vehicle body, many concept design methodologies have been studied. However, study using database would be not conducted yet. Therefore, this paper presents body structure development process using joint database and multi-disciplinary design optimization. The suggested process was constructed with 4-phase. First phase is knowledge-based template construction. Knowledge-based template is consisted of geometry database and performance database. To construct joint database, it is necessary to evaluate joint’s cross section. In second phase, body structure conceptual design using joint database is progressed. For joint’s section selection, what-if design method is used. In addition, implicitly parametric geometry model is used to realize easily shape or topology changes. Parametric geometry model was constructed using SFE CONCEPT. In the last phase, body structure detail design using robust design optimization method is fulfilled. Considering the deviation of thickness design variables, six-sigma terms added into the inequality constraints for bending stiffness and torsional stiffness and equality constraints for 1st bending mode and 1st torsion mode.

거대 로봇의 관절 리디자인(Re-design) 연구 - 1970년대 국내 거대 로봇, `황금날개 3호 청동거인`을 중심으로 -

김치훈 ( Kim Chee-hoon ) 한국디자인트렌드학회 2012 한국디자인포럼 Vol.34 No.-

1970년대 디자인된 거대로봇의 경우 셀 애니메이션 제작 하에서는 모든 동작 구현이 가능했다. 더욱이, 당시에는 관절이나 몸의 움직이는 범위를 세심하게 설계할 필요성을 느끼지 못했다. 그러나 오늘날 3D 애니메이션으로 당시의 거대 로봇 디자인을 그대로 사용해서 작업해야 하는 경우에는 관절과 관절의 무수한 간섭 혹은 상충 현상이 나타나기 때문에 자연스럽고도 격렬한 격투 동작을 표현하는데 한계가 따른다. 결국 로봇의 원형을 최대한 유지하는 것을 전제로 관절의 재설계(Redesign)를 통해 이러한 문제점을 보완해야한다. 따라서 본 연구는 인체관절을 분류하여 특징을 알아보고, 거대 로봇에 적용될 수 있는 관절을 도출한다. 그리고 원형 디자인을 유지하면서도 자유로운 동작이 가능한 반다이(Bandai)와 카이요도(Kaiyodo) 피규어(Figure) 모델을 리서치한 후 적용할 수 있는 관절을 국내 거대 로봇 중 `황금날개 3호 청동거인`에 맞게 수정하고 이식하여 원형 유지와 함께 최대한의 활동범위를 확보한다. 이로 인해 3D 애니메이션 제작과 함께 피규어 산업의 효율성도 높일 수 있을 것으로 기대한다. There was not any problem to animate the various motion and action of 1970`s super robots in cell animation. It was not necessary to consider about rotational and sliding joints that defined the range of the movement for robots at that time. However, the careless joints of the robots bring the trouble making 3D animation today. It is impossible to realize active movement or fighting action for the original designed 1970`s super robots because the joints should be interference or collision each other when they rotate. For the best solution, the joints of the super robot must be re-designed in retaining its original form. This study is categorized and characterized about human body`s joints then it is applied for super robots` joints. This is researched about joints of robot toys or action figures such as Bandai and Kaiyodo ones and it will be applied the newly designed the joints for the original 1970`s Korean super robot, `Gold Wing, the 3rd TALOS`. It will not only raise the efficiency of the process of 3D animation but also share with toy industries.

AL/폴리머 접착제 접합부의 강도향상을 위한 접합설계에 관한 연구

오귀호(Kwi-Ho Oh),서문훈(Mun-Hun Seo) 산업기술교육훈련학회 2009 산업기술연구논문지 (JITR) Vol.14 No.4

In the study, this study aims at focusing joint shape types which could affect strength and durability of Al/Polymer lap joints as the fundamental research of design of adhesive bonding joints. In this research, several joint shape types were adopted to evaluate their effects on the adhesive strength: Plain Single Lap, Trigonal Single Lap, Trigonal Edged Single Lap, Bevelled Lap, Joggled Lap, Double Lap. The results are summarized as follows: When shear-tensile load is applied on the lap joint specimen using adhesive bond, maximum load was mainly distributed on the edge of lap joint. It is confirmed by the experiment based on the documents. Joint shapes of lap joint highly may affects to durability. When shear-tensile load applies, durability of adhesive bonding specimen is better than of spot-weld specimen. It is known than adhesive bonding method can replace spot weld. In the plastic/aluminum specimen, trigonal edged single lap and bevelled lap joint have a lot of strength improvement effect. Load speed rate (CHS) affects to adhesive strength design uniformly as load rate and shear-tensile load increases. Fracture parts move from stress concentrated edge to center as interfacial fracture increases.

차량 B.I.W 강성과 경량화를 고려한 사이드 단면 최적설계 프로그램 개발

유윤기(Yun Ki You),임홍재(Hong Jae Yim),김기창(Ki Chang Kim) 한국자동차공학회 2006 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

In the primary design step. an accurate and efficient design guide is important for design engineers. Otherwise design engineers have to go through trial and error for the desired design. In this paper, an integrated design program is presented. The presented design program named B-SOPT(Beam Section Optimization) provides an accurate and efficient design guide for the frame cross section of the vehicle side body structure. Therefore, using the B-SOPT, design engineers could find an optimum design of the pillar section without waste of time and energy in the primary design step. The B-SOPT is composed of vibration analysis, section property analysis and section optimization. Vibration analysis procedure is necessary to obtain target constraint(section property) for optimization. B.I.W vibration analysis model can be generated and joint stiffness also can be generated automatically by explicit formula derived using RSM (Response surface method) in the B-SOPT. For design engineers, B-SOPT is established for graphic user interface environment by visual C++. A design example is given to demonstrate the design procedure using the B-SOPT program.

Seismic resistance of exterior beam-column joints with non-conventional confinement reinforcement detailing

Bindhu, K.R.,Jaya, K.P,Manicka Selvam, V.K. 국제구조공학회 2008 Structural Engineering and Mechanics, An Int'l Jou Vol.30 No.6

The failure of reinforced concrete structures in recent earthquakes caused concern about the performance of beam column joints. Confinement of joint is one of the ways to improve the performance of beam column joints during earthquakes. This paper describes an experimental study of exterior beam-column joints with two non-conventional reinforcement arrangements. One exterior beam-column joint of a six story building in seismic zone III of India was designed for earthquake loading. The transverse reinforcement of the joint assemblages were detailed as per IS 13920:1993 and IS 456:2000 respectively. The proposed nonconventional reinforcement was provided in the form of diagonal reinforcement on the faces of the joint, as a replacement of stirrups in the joint region for joints detailed as per IS 13920 and as additional reinforcement for joints detailed as per IS 456. These newly proposed detailing have the basic advantage of reducing the reinforcement congestion at the joint region. In order to study and compare the performance of joint with different detailing, four types of one-third scale specimens were cast (two numbers in each type). The main objective of the present study is to investigate the effectiveness of the proposed reinforcement detailing. All the specimens were tested under reverse cyclic loading, with appropriate axial load. From the test results, it was found that the beam-column joint having confining reinforcement as per IS: 456 with nonconventional detailing performed well. Test results indicate that the non-conventionally detailed specimens, Type 2 and Type 4 have an improvement in average ductility of 16% and 119% than their conventionally detailed counter parts (Type1 and Type 3). Further, the joint shear capacity of the Type 2 and Type 4 specimens are improved by 8.4% and 15.6% than the corresponding specimens of Type 1 and Type 3 respectively. The present study proposes a closed form expression to compute the yield and ultimate load of the system. This is accomplished using the theory of statics and the failure pattern observed during testing. Good correlation is found between the theoretical and experimental results.

Parameter Sensitivity Analysis of a New Fabricated Rectangular Tunnel Joint Using Numerical Method

Zhen Huang,Chenlong Zhang,Shaokun Ma,Hai Zhang,Zhang Zhou,Hongzhou Li 대한토목학회 2022 KSCE Journal of Civil Engineering Vol.26 No.2

An assembled rectangular tunnel has the advantages of high space utilization rate and strong urban applicability. This solution has been widely used in urban underground traffic construction. During their construction and operation, the joints are the weakest parts of the structure. The mechanical behavior of joints is closely related to the safety of the tunnel; thus, it is important to use a joint with good mechanical behavior. This study presents a new type of joints for shallow buried assembled rectangular tunnels. To evaluate the effect of design parameters (tenon depth and tenon angle) on the behavior of joints, the finite element method was used. At the same time, the mechanical behavior of rectangular tunnel joint was analyzed and compared with that of a traditional straight joint under the same loading conditions, showing better results. The performance-based engineering (PBE) concept was implemented to evaluate the robustness of rectangular tunnel joints. The results show that if the bolt is placed on the tensile side of the structure, it provides a strong restraining effect on the deformation of the joint. When the tenon depth and angle are 0.8 m and 3.6°, respectively, the overall behavior of the rectangular tunnel joint was improved. The new type of assembled rectangular tunnel joint designed in this study has a good application prospect in a shallow stratum and provides new ideas for the design and construction of such tunnels.

REDUCTION OF GENERATED AXIAL FORCE BY CONSTANT VELOCITY JOINT USING CONTACT OPTIMIZATION OF TRIPOD JOINT

위준희,이광희,이철희 한국자동차공학회 2020 International journal of automotive technology Vol.21 No.4

Constant velocity (CV) joints are the primary component of a vehicle that transmits the driving force from an engine/transmission to a wheel at a constant speed. A CV joint comprises numerous mechanical parts. The roller and housing are in contact and, therefore, subjected to contact stresses. Contact stress causes sliding friction because of microslip in the contact area inside the CV joint. This internal friction generates an axial force, dependent on the kinematics. A generated axial force (GAF) is caused by the internal friction in a plunging-type CV joint. This force can have a direct impact on the degradation of the noise, vibration, and harshness characteristics of a vehicle. The typical vibration of a CV joint transmitted to the vehicle is shudder, which degrades the lateral oscillation of the vehicle. Shudder is generated by the GAF and results from the rotation of the CV joint during rapid acceleration, stimulating the lateral movement of the vehicle and causing discomfort to passengers. In this study, the radii of the roller and the housing were selected as the design parameters, and the contact stress was minimized through the sensitivity analysis. The GAF of the existing CV joint and optimized CV joint are compared through a multibody dynamic simulation. An axial force test is performed on the CV joint of a C-segment vehicle to verify the dynamic simulation results. The friction characteristics of the greases used in the CV joint were also confirmed by the schwingung reibung verschleiss (SRV) friction test. The results obtained can be used to reduce the GAF of the CV joint and to build an optimized CV joint model.