• 화약ㆍ발파
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• 제31권2호
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• pp.50-58
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• 2013

발파공사 현장 주변에는 많은 종류의 보안물건이 존재하고 있어 발파진동의 영향을 저감하기 위해 각 기관별로 발파진동 허용기준을 제시하고 있다. 그러나 현재 적용되고 있는 발파진동 허용기준은 지나치게 강화 적용하여 공사비 증가와 공기 연장의 폐해가 발생하고 있는 실정이다. 본 연구에서는 기존 설계와 시공사례 등을 토대로 적용된 발파진동 허용기준을 검토하고 그 문제점을 분석하여 합리적인 발파진동 허용기준을 산출하는 방법을 제안하고자 한다.

• 한국소음진동공학회논문집
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• 제12권7호
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• pp.527-533
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• 2002

A railway vehicle should be satisfied with the safety criteria and ride comfort of passengers. A bogie of railway vehicle Is composed of many suspension components, such as springs, dampers and etc.. that have an influence on the dynamic behavior of the train wish the wheel/rail profiles and track geometries. Therefore, it Is necessary for engineers to check the Interference between vehicle limit and construction limit with considering the vehicle's behavior, because when the vehicle is running on curved track, it should be have enough clearance from infrastructure for safely, spacially In a subway system. This paper explains the effective method of analysis for vehicle limit considering the vehicle dynamic behavior and reviews the problem of vehicle limit for the Korean Standard Urban Train. The results show that the vehicle limit is over the construction limit when the Korean Standard Urban Train runs on the curved track with 180 m radius of curve.

• Geomechanics and Engineering
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• 제15권5호
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• pp.1039-1046
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• 2018

This paper presents a limit analysis of the series of construction stages of shallow tunneling method by investigating their respective safety factors and failure mechanisms. A case study for one particular cross-section of Beijing Subway Line 7 is undertaken, with a focus on the effects of multiple soil layers and construction sequencing of dual tunnels. Results show that using the step-excavation technique can render a higher safety factor for the excavation of a tunnel compared to the entire cross-section being excavated all at once. The failure mechanisms for each different construction stage are discussed and corresponding key locations are suggested to monitor the safety during tunneling. Simultaneous excavation of dual tunnels in the same cross-section should be expressly avoided considering their potential negative interactions. The normal and shear forces as well as bending moment of the primary lining and locking anchor pipe are found to reach their maximum value at Stage 6, before closure of the primary lining. Designing these struts should consider the effects of different construction stages of shallow tunneling method.

• 건설안전기술
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• 통권47호
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• pp.56-62
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• 2008

In order to apply the Limit Equilibrium Method generally used for the slope stability analysis to the vertical excavation walls reinforced by soil-nailing, in this study, the Limit Equilibrium Method for the temporary shoring facilities reinforced by soil-nailing was proposed, which is based on the stability for the horizontal displacement. In this study, the relation of the internal friction angles of the ground and the vertical excavation depths was arranged, which is satisfying the stability on the horizontal displacement by using the verification of the Limit Equilibrium Method. And then, the rational reinforcing length of soil-nailing was proposed for the critical areas. In addition, the modified safety ratio satisfying the stability on the horizontal displacement was proposed, when the Limit Equilibrium Method was applied to the vertical excavation walls reinforced by soil-nailing.

• 한국산업융합학회 논문집
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• 제7권2호
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• pp.181-186
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• 2004

This study presents a optimization of structure, in which constraints contain the conditions of stress and serviceability, while the sequential linear programming method (SLP) is used as a rational approach. The optimum design results contained on the limit state constraints are compared with those obtained by the only stress and ministry of construction enacted standard plans. A simple slab bridge is analysed numerically for illustration of the structural optimization. It may be asserted that serviceability constraints is very important to a structure design.

• 한국구조물진단유지관리공학회 논문집
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• 제6권1호
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• pp.131-140
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• 2002

In this paper, a limit state model based on the analysis of structural behavior of segmental prestressed concrete box girder bridges and reliability-based safety assessment method are proposed for the bridges erected by free cantilever method. Strength limit state models for prestressed concrete box girder and rigid-frame type columns are developed for a structural safety assessment during construction. Based on the proposed limit state models, the reliability of the bridge is evaluated by using the Advanced First Order Second Moment method. The proposed model and method are applied to the Seo-Hae Grand Bridge built by FCM in order to verify its effectiveness in the safety assessment during construction of the kind of bridges. The sensitivity analyses of the main parameters are also performed in order to identify the important factors that need to be controlled for the safety of the bridges during construction.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 춘계 학술발표회
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• pp.1279-1285
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• 2010

Our country has a tendency to build many structures by cutting mountainous areas due to geographical features. Among these construction done in our country, road construction take the first spot in rank. As the construction is done, fractured inclining plane is created inevitability because of the natural properties of mountainous areas. The stability of the fractured inclining planes and slope formed in the opening, which are developed at the time of construction, need to be evaluated. Also, reinforcement plans for these matters are necessary. This paper is to go through an examination on the fractured inclining surface that is developed at the time of construction, especially the composite inclining plane that consists of soil and rocks. Furthermore, evaluating the stability by performing an analysis on stereographic projection and limit equilibrium, based on the examination results. using the stability evaluations, applications were explored for reinforcement methods of construction that fits the geological characters of this inclining surface.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2014년도 추계 학술논문 발표대회
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• pp.30-31
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• 2014

Since consists of regression equation by penetration depth prediction calculated by existing NDRC formula mainly considers properties of projectile, impact velocity, compressive strength as parameter, it is difficult to apply it to fire reinforced concrete. In this study, scabbing limit thickness was predict considering fiber reinforcement effect by local fracture of concrete was evaluated through high-velocity impact test. As a result of applying fracture reduction coefficient to NDRC, it was possible to predict scabbing limit thickness of fiber reinforced concrete similarly with actual measurement.

• 한국ITS학회 논문지
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• 제15권6호
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• pp.138-149
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• 2016

본 연구는 가상주행 시뮬레이터 실험을 통해 악천후시 가변 제한속도 표출 효과를 검토하였다. 본 연구는 기상변화 없이 제한속도를 낮추어 표출한 경우와 기상이 변화되었는데도 제한속도를 낮추어 표출하지 못한 경우는 운전자의 기대심리를 위배한 것으로 기상 변화에 따라 속도를 감속 표출하는 것에 비해 상대적으로 안전 측면에서 바람직하지 못하다고 가정하고 이를 가상주행 시뮬레이터 결과를 통해 검토하였다. 본 연구는 운전자의 기대심리에 부합되는 정도를 나타내는 지표로 운전자 순응도를 선택하였고, 이를 정량화하기 위한 수단으로 표출 제한속도를 포함한 일정 속도구간 내 누적확률밀도를 이용하였다. 검토결과, 운전자의 기대심리를 위배하였다고 가정한 조건들이 비교그룹에 비해 상대적으로 운전자의 주행행태적 측면에서 부정적인 것으로 평가되었다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2004년도 춘계학술발표회
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• pp.580-585
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• 2004

The purpose of this study is the stability evaluation of soil slope according to inclination of upper natural slope. Upper natural slope breeds loss of slope by inflow in slope of surface water by rainfal1 and f1uctuation of amount of materials in slope through method of cutting slope according to degree of inclination. Basis of standard inclination does not consider of inclination of upper natural slope and is presented uniformly. Therefore, in this study, analyzed stability of inclination of upper natural slope through limit equilibrium analysis. Result is same as following. First, safety factor through limit equilibrium analysis is almost direct decrease when gradient of soil slope is 1:1.2, 1:1.5. However, when gradient of soil slope is 1:1.0, 1:0.7, if sinclination of upper natural slope are $20^{\circ}$, it shows tendency that decrease of safety factor becomes low rapidly. Second, when when gradient of soil slope is fixed, inclination of upper natural slope increase tendency(maximum 3.0 times) that decrease of safety factor.