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.

자기공명영상에서 관찰되는 측두하악관절의 관절강내 삼출과 동통 및 관절원판 변위와의 관계

유상수,기우천,최재갑,Ryu, Sang-Soo,Kee, Woo-Cheon,Chol, Jae-Kap 대한안면통증구강내과학회 2000 Journal of Oral Medicine and Pain Vol.25 No.1

The authors assessed if there is a relationship between joint effusion and the presence of pain, and between joint effusion and disc displacement in 446 temporomandibular joints of 223 subjects who visited the Department of Oral Medicine, Kyungpook National University Hospital with the complaints of temporomandibular joint problem. The amount of joint effusion and the position of disc were determined from magnetic resonance images of the temporomandibular joints. The position of disc was classified into normal disc position, disc displacement with reduction (DDWR), and disc displacement without reduction (DDWOR). The amount of joint effusion was graded according to the extent of joint area of high signal intensity on T2-weighted MR images. These findings were correlated with one another and statistically analyzed. The results were as follows; 1. The incidence of temporomandibular joint pain Was higher in the joints with higher amount of joint effusion (P<0.001). 2. The proportion of temporomandibular joints with higher amount of effusion increased in the joints with more advanced articular disc displacement (P<0.001).

Dynamic Performance and Stress Wave Propagation Characteristics of Parallel Jointed Rock Mass Using the SHPB Technique

Qirui Wang,Erxiang Song,Peng Xu,Yongsheng He,Xiaoyan Shi,Huanzhen Xie 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.5

To investigate the effects of joint number on dynamic compressive strength, crushing effect, stress wave propagation, stress wave conversion, and energy evolution of rock masses, SHPB and LS-DYNA were used to conduct impact experiments and numerical simulations, respectively. The results demonstrate that the dynamic strength of a multi-jointed (two- and three-jointed) rock are 11.1 and 25.1% lower, respectively, compared with that of a single-jointed rock. The weak surface near the joint causes the rock mass to crack first. The rock cracking time advances significantly as the joints number increases. The reflection coefficient falls as the number of joints increases, because the wave impedance of the joint differs from that of the rock. The transmission coefficient, however, is exactly the reverse. When the P wave strikes the specimen, the vibration direction of the particles is deflected at the joint, resulting in a shear wave. P waves are reflected and superimposed between joints, increasing the strength of shear waves and resulting in more transverse cracks in multi-jointed rock masses under dynamic loading. Meanwhile, the total energy consumed by a bedrock under dynamic loading is obviously larger than that of joints. However, the total energy absorbed by joints exceeds that of the bedrock when the joints number increases. The results further enrich the dynamic basis of jointed rock masses.

Z shape joints under uniaxial compression

Sarfarazi, Vahab,Asgari, Kaveh,Mahshoori, Ali Reza Techno-Press 2021 Advances in concrete construction Vol.12 No.2

In this paper, the effects of angle of Z shape non-persistent joint on the compressive behaviour of joint's bridge area under uniaxial compression load have been investigated. Furtheremore experimental test and Particle flow code in two dimension (PFC2D) have been used. concrete samples with dimension of 50 mm×50 mm×100 mm were prepared. Tensile strength of model material was 1 MPa. Within the specimen, three Z shape non-persistent notches were provided. The notch length was 1.5 cm. when two upper and lower notch have horizontal direction, the middle joint angle were 45°, 90° and 135°. When dips of two upper and lower notch was 90°, the middle joint angle were 45°, 90° and 135° degree. When dips of two upper and lower notch was 135 degree, the middle joint angle were 45°, 90° and 135°. Totally, 9 different configuration systems were prepared for Z shape non-persistent joints. Also, 37 models with different Z shape non-persistent notch angle were prepared in numerical model. The axial load with rate of 0.005 mm/s was applied to the model. Results indicated that the failure process was mostly governed by the Z shape non-persistent joint angle. The compressive strengths of the specimens were related to the fracture pattern and failure mechanism of the discontinuities. In addition it was shown that the compresssive behaviour of discontinuities is depend on the number of the induced tensile cracks which are increased by increasing the middle joint angle. The middle joint has significant effect on the failure pattern. In fixed upper and lower joints angles, when the middle joint angle is 90° the failure stress has maximum value. On the other hand, it has minimum value when the middle joint angle was 135°. In fixed middle joint angle, the samples have minimum value when the upper and lower joints angles are 135°. At the end, the failure pattern and strength results of the experiential tests and the numerical simulations were similar.

Effects of Un cracked Joints in Jointed Concrete Pavements

Beom Jun Chon,Seung Woo Lee 대한토목학회 2007 KSCE journal of civil engineering Vol.11 No.3

Joints in jointed concrete pavements are artificially designed discontinuities to control the natural cracking with slab movements caused by changes in temperature and moisture conditions. However, considerable portion of joints are not cracked in practice. In this study, joint-uncracking phenomenon are categorized by two patterns, prior mid-slab cracking pattern (Case A) and low tensile-stress pattern (Case B). Prior mid-slab cracking pattern indicates that mid-slab cracking occurs before saw cutting at joints and joints remains as uncracked. Low tensile-stress pattern indicates that some portions of joint are cracked and others remains uncracked without mid-slab cracking since tensile stress, developed by subbase friction and curing, is lower than minimum stress to crack at joints. The causes of and frequencies of joint-uncracking are investigated in a number of jointed concrete pavements (JCP) in USA and Korea. The uncracked joints result in longer-concrete-pavement slab than the designed. In this study, the effects of uncracked joints such as the erratic large joint opening and excessive slab stress are explored.

한국군의 합동성 강화를 위한 새로운 접근

조태근 ( Jo¸ Taegun ) 한국군사학회 2023 군사논단 Vol.115 No.-

In modem warfare, it has become impossible to talk about war and operations except for jointness. Since World War I, most wars have been conducted through joint operations, and its effectiveness has been proven in the Gulf War and the Irag War. In the ongoing Russo - Ukrainian War, the cause of Russia’s difficulties can be found in the lack or jointness. The ROK military also recognizes the importance or jointness and has been implementing a comprehencive plan to strengthen jointness since 2005. In 2006, many efforts were made to strengthen jointaess, such as enacting the National Defense Reform Act. However, despite these efforts, the South Korean military failed to respond effectively to the sinking of the Cheonan warship, die attack on Yeonpyeong Island, and the 2022 UAV provocation, and received many reprimands from the public. The study started with the question “Why has jointness not been achieved despite many efforts to strengthen jointness?” Jointness is not improved by being emphasized at any moment. The South Korean government and military referred the cases of advanced countries such as the US strengthen jointness, but overlooked the root cause of the jointness problem. Jointness can be divided into physical and psychological domains, and the Korean military has put a lot of effort into the physical part. However, if you look at the root cause of the jointness problem, you can see that the psychological part plays a big part. In this study, while accurately recognizing the root cause of the jointness problems, we proposed four new approaches to strengthening the jointness of the Korean Military.

한국군의 합동성 문제 고찰: 인식에 기초한 평가와 해결책

장재규 세종연구소 2022 국가전략 Vol.28 No.4

Military joint refers to joint activities, organizations, and operations of the Army, Navy, and Air Force, and jointness is a desirable characteristic that joint should have for synergistic effects. Since the concept of cross-domain synergy was presented, the view has shifted from military service to domain-centered combat power integration. The purpose of this study is to diagnose the level of jointness of the Korean military and present tasks and directions for improving jointness. To this end, this study summarizes the concept of jointness and cross-domain synergy as a theoretical consideration, and evaluates the jointness of the Korean military using the survey results. And based on the evaluation, tasks and directions for improving jointness are proposed. As a result of the study, the level of jointness of the Korean military was evaluated as “coordinated” - the second step of jointness, and three high-priority tasks were derived: joint special operation development, joint cyber and space capability development, and joint education development.

Joint moments and contact forces in the foot during walking

Kim, Yongcheol,Lee, Kyoung Min,Koo, Seungbum Elsevier 2018 Journal of biomechanics Vol.74 No.-

<P><B>Abstract</B></P> <P>The net force and moment of a joint have been widely used to understand joint disease in the foot. Meanwhile, it does not reflect the physiological forces on muscles and contact surfaces. The objective of the study is to estimate active moments by muscles, passive moments by connective tissues and joint contact forces in the foot joints during walking. Joint kinematics and external forces of ten healthy subjects (all males, 24.7 ± 1.2 years) were acquired during walking. The data were entered into the five-segment musculoskeletal foot model to calculate muscle forces and joint contact forces of the foot joints using an inverse dynamics-based optimization. Joint reaction forces and active, passive and net moments of each joint were calculated from muscle and ligament forces. The maximum joint reaction forces were 8.72, 4.31, 2.65, and 3.41 body weight (BW) for the ankle, Chopart’s, Lisfranc and metatarsophalangeal joints, respectively. Active and passive moments along with net moments were also obtained. The maximum net moments were 8.6, 8.4, 5.4 and 0.8%BW∙HT, respectively. While the trend of net moment was very similar between the four joints, the magnitudes and directions of the active and passive moments varied between joints. The active and passive moments during walking could reveal the roles of muscles and ligaments in each of the foot joints, which was not obvious in the net moment. This method may help narrow down the source of joint problems if applied to clinical studies.</P>

어깨관절 질환에 대한 관절가동술 유형의 연구 동향 : 주제범위 문헌고찰

이정우,이남기 대한통합의학회 2023 대한통합의학회지 Vol.11 No.3

Purpose : This study sought to investigate research trends regarding joint mobilization type among patients with shoulder joint diseases. Methods : A scoping review was conducted according to the five steps outlined by Arskey and O’Malley and PRISMA-ScR. We searched six domestic databases (ScienceOn, DBpia, Riss, Kmbase, Kiss, KCI) and three international databases (CINAHL, Pubmed, Cochrane central) between 2013 and June 2023. The keyword terms used were ‘joint mobilization’, ‘Kaltenborn’, ‘Maitland’, ‘Mulligan’, and ‘shoulder joint’. Results : There were a total of 44 studies that investigated the topic, and these were divided into quantitative analysis and topic analysis. In terms of publication year, the number of studies within the last five years has increased more than compared to the previous five years, with most of them being randomized clinical trials. In shoulder joint diseases, it was found that the majority of joint movement studies focused on adhesive joint cystitis and shoulder collision syndrome. The Mulligan concept was the most commonly studied type of joint motion. The dependent variables used included pain, joint function (disability), and muscle function. The visual analog scale was the most commonly used for the pain variable, followed by the numeric rating scale. For joint function and disability variables, range of motion was the most commonly used, followed by shoulder pain and disability index, and disabilities of the arm, shoulder, and hand. For muscle function, variables such as muscle tone, strength, and activity were used. Conclusion : We believe that findings of this scoping review can serve as valuable mapping data for joint mobilization research on shoulder joint diseases. Further studies including systematic reviews and meta-analyses based on these results are recommended.

공유특허권의 지분에 대한 무효심판청구의 문제 - 대법원 2015. 1. 15. 선고 2012후 2432 판결을 중심으로 -

장낙원,정태호 한국정보법학회 2017 정보법학 Vol.21 No.1

Restrictions concerning joint ownership of patent right also exist in a request for the trial under the Patent Act. When a petition is filed for trial against patentees who jointly hold a patent, all such joint-holders shall be made defendants[Article 139(2) of the Patent Act] and When joint-holders of a patent or an entitlement to a patent file a petition for trial onthe jointly-held right, all joint-holders shall file the petition jointly[Article 139(3) of the Patent Act]. On the other hand, possibility of a request for the invalidation trial against the share of joint ownership of patent right can come into question despite of the aboveprovisions. Supreme Court Decision 2012Hu2432(hereinafter referred to as “the subject decision”) decided that a request for the invalidation trial against the share of joint ownership of patent right has an unlawful defect. It is reasonable that the subject decision didn’t accept a request for the invalidation trial against the share of joint ownership of patent right by acknowledging the unity of disposition of a patent as the object of the invalidation trial. The above decision accords with being decided that all joint-holders shall be parties of invalidation suit or invalidation trial in USA, Germany and Japan. On the other hand, according to Article 99-2 of the revised Patent Act, it is now possible for a legitimate right-holder to directly claim the transfer of the share of the joint ownership of patent right from Unentitled share-holders without the need of a request for the invalidation trial against joint ownership of patent right. In conclusion, a request for the invalidation trial against the share of joint ownership of patent right becomes impossible by the subject decision and practical advantage got to disappear in the discussions on this subject by that provision of the revised Patent Act. 특허권의 공유에 관련된 제한은 특허법상 심판청구에서도 존재하는데, 공유특허권의 특허권자에 대하여 심판을 청구하는 때에는 공유자 모두를 피청구인으로 하여야하고(특허법 제139조 제2항), 특허권의 공유자가 그 공유인 권리에 관하여 심판을 청구하는 때에는 공유자 모두가 공동으로 청구하여야 한다(특허법 제139조 제3항). 그런데 이상의 규정에도 불구하고 공유특허권의 지분의 공유자가 다른 공유자의 지분에 대해서 무효심판청구가 가능한지 여부가 문제로 될 수 있다. 대법원 2012후2432 판결(이하, “대상판결”이라 한다)에서는 공유특허권의 지분에대한 무효심판청구를 부적법하다고 판단하였다. 대상판결이 무효심판대상으로서의특허처분의 단일성을 인정하여 공유특허권의 지분에 대한 무효심판청구를 허용하지않은 것은 타당하다고 생각된다. 이것은 미국, 독일, 일본에서 공유자 전원이 무효소송이나 무효심판의 당사자가 되어야 한다고 해석되는 것과도 부합한다. 한편으로 개정 특허법 제99조의2에 의해서 공유특허권에 대하여 정당한 권리자가무효심판을 청구할 필요 없이 공유특허권의 지분의 이전을 무권리자인 공유지분권자를 상대로 직접 청구할 수 있게 되었다. 따라서 공유특허권의 지분에 대한 무효심판청구는 대상판결에 따라 불가능하게 되었을 뿐만 아니라, 개정 특허법상의 해당 규정에 의해 이것에 관한 실제적인 논의의 실익이 없게 되었다