• 제목/요약/키워드: Deep Excavations

검색결과 55건 처리시간 0.065초

도심지 깊은 굴착으로 발생하는 인접 지반 지표침하 분석 (Analysis of Perimetrical Ground Settlement Behavior for Deep Excavations in Urban Areas)

  • 양구승;김명모
    • 한국지반공학회지:지반
    • /
    • 제13권2호
    • /
    • pp.101-124
    • /
    • 1997
  • 풍화토 및 모래질 충적토가 암반위에 쌓인 형태로 구성된 국내 수도권 도심 지역에서, 깊은 굴착 공사로 인하여 발생하는 인접 지표의 침하에 대해 현장 측정을 중심으로 연구를 수행하였다. 먼저, 토류벽 설치, 중간 말뚝 설치 등 본격적인 굴토 공사가 진행되기 이전의 공정으로 인한 인접 지표침하량, 침하 영향거리 등을 측정, 분석하였으며 다음으로, 본격적인 굴토로 인하여 발생하는 인접 지표의 침하에 대해 침하량, 침하 영향거리 등을 측정, 분석하고 균질한 사질토 지반이나 단단한 점토 지반에 대해 기존에 제시된 연구 결과와 비교하였다. 또한 굴착 공사시 과도한 변형으로 인하여 인접 지표 및 구조물에 균열 등의 피해가 발생한 7개 현장 사례를 통하여 굴착 공사로 인한 인접 지표의 균열 발생 범위에 대하여 분석하였다.

  • PDF

도심지 깊은굴착시 주변 건물 및 매설관 손상평가 (Deep Excavation-induced Building and Utility Damage Assessment)

  • 유충식
    • 한국지반공학회:학술대회논문집
    • /
    • 한국지반공학회 2002년도 가을 학술발표회 논문집
    • /
    • pp.85-95
    • /
    • 2002
  • A substantial portion of the cost of deep excavations in urban environments is devoted to prevent ground movements and their effects on adjacent buildings and utilites. Prediction of ground movements and assessment of the risk of damage to adjacent structures has become an essential part of the planning, design, and construction of a deep excavation project in the urban environments. This paper presents damage assessment techniques for buildings and utilities adjacent deep excavation, which can be readily used in practice.

  • PDF

Investigation of crack growth in a brick masonry wall due to twin perpendicular excavations

  • Mukhtiar Ali Soomro;Dildar Ali Mangnejo;Naeem Mangi
    • Geomechanics and Engineering
    • /
    • 제34권3호
    • /
    • pp.251-265
    • /
    • 2023
  • In urban construction projects, it is crucial to evaluate the impacts of excavation-induced ground movements in order to protect surrounding structures. These ground movements resulting in damages to the neighboring structures and facilities (i.e., parking basement) are of main concern for the geotechnical engineers. Even more, the danger exists if the nearby structure is an ancient or masonry brick building. The formations of cracks are indicators of structural damage caused by excavation-induced ground disturbances, which pose issues for excavation-related projects. Although the effects of deep excavations on existing brick masonry walls have been thoroughly researched, the impact of twin excavations on a brick masonry wall is rarely described in the literature. This work presents a 3D parametric analysis using an advanced hypoplastic model to investigate the responses of an existing isolated brick masonry wall to twin perpendicular excavations in dry sand. One after the other, twin perpendicular excavations are simulated. This article also looks at how varying sand relative densities (Dr = 30%, 50%, 70%, and 90%) affect the masonry wall. The cracks at the top of the wall were caused by the hogging deformation profile caused by the twin excavations. By raising the relative density from 30% to 90%, excavation-induced footing settlement is greatly minimized. The crack width at the top of the wall reduces as a result of the second excavation in very loose to loose sand (Dr = 30% and 50%). While the crack width on the top of the wall increases owing to the second excavation in medium to very dense sand (Dr = 70% and 90%).

A multivariate adaptive regression splines model for estimation of maximum wall deflections induced by braced excavation

  • Xiang, Yuzhou;Goh, Anthony Teck Chee;Zhang, Wengang;Zhang, Runhong
    • Geomechanics and Engineering
    • /
    • 제14권4호
    • /
    • pp.315-324
    • /
    • 2018
  • With rapid economic growth, numerous deep excavation projects for high-rise buildings and subway transportation networks have been constructed in the past two decades. Deep excavations particularly in thick deposits of soft clay may cause excessive ground movements and thus result in potential damage to adjacent buildings and supporting utilities. Extensive plane strain finite element analyses considering small strain effect have been carried out to examine the wall deflections for excavations in soft clay deposits supported by diaphragm walls and bracings. The excavation geometrical parameters, soil strength and stiffness properties, soil unit weight, the strut stiffness and wall stiffness were varied to study the wall deflection behaviour. Based on these results, a multivariate adaptive regression splines model was developed for estimating the maximum wall deflection. Parametric analyses were also performed to investigate the influence of the various design variables on wall deflections.

Characteristics and prediction methods for tunnel deformations induced by excavations

  • Zheng, Gang;Du, Yiming;Cheng, Xuesong;Diao, Yu;Deng, Xu;Wang, Fanjun
    • Geomechanics and Engineering
    • /
    • 제12권3호
    • /
    • pp.361-397
    • /
    • 2017
  • The unloading effect from excavations can cause the deformation of adjacent tunnels, which may seriously influence the operation and safety of those tunnels. However, systematic studies of the deformation characteristics of tunnels located along side excavations are limited, and simplified methods to predict the influence of excavations on tunnels are also rare. In this study, the simulation capability of a finite element method (FEM) considering the small-strain characteristics of soil was verified using a case study. Then, a large number of FEM simulations examining the influence of excavations on adjacent tunnels were conducted. Based on the simulation results, the deformation characteristics of tunnels at different positions and under four deformation modes of the retaining structure were analyzed. The results indicate that the deformation mode of the retaining structure has a significant influence on the deformation of certain tunnels. When the deformation magnitudes of the retaining structures are the same, the influence degree of the excavation on the tunnel increased in this order: from cantilever type to convex type to composite type to kick-in type. In practical projects, the deformation mode of the retaining structure should be optimized according to the tunnel position, and kick-in deformation should be avoided. Furthermore, two methods to predict the influence of excavations on adjacent tunnels are proposed. Design charts, in terms of normalized tunnel deformation contours, can be used to quantitatively estimate the tunnel deformation. The design table of the excavation influence zones can be applied to determine which influence zone the tunnel is located in.

인공신경망기법을 이용한 깊은 굴착에 따른 지표변위 예측 (Prediction of Deep-Excavation induced Ground surface movements using Artifical Neural Network)

  • 유충식;최병석
    • 한국지반공학회:학술대회논문집
    • /
    • 한국지반공학회 2002년도 가을 학술발표회 논문집
    • /
    • pp.451-458
    • /
    • 2002
  • This paper presents the prediction of deep excavation-induced ground surface movements using artificial neural network, which is of prime importance in the perspective of damage assessment of adjacent buildings. A finite element model, which can realistically replicate deep-excavation-induced ground movements was employed and validated against available large-scale model test results. The validated model was then used to perform a parametric study on deep excavations with emphasis on ground movements. Using the result of the finite element analysis, Artificial Neural Network(ANN) system is formed, which can be used in the prediction of deep exacavation-induced ground surface displacements. The developed ANN system can be effecting used for a first-order prediction of ground movements associated with deep-excavation.

  • PDF

인공신경망 기법을 활용한 굴착공사 흙막이 변위량 예측에 관한 연구 (A Study on Neural Networks Forecast Model of Deep Excavation Wall Movements)

  • 신한우;김광희;김용석
    • 한국건축시공학회지
    • /
    • 제7권3호
    • /
    • pp.131-137
    • /
    • 2007
  • To predict deep excavation wall movements is important in the urban areas considering the cost and the safety in construction. Failing to estimate deep excavation wall movements in advance causes too many problems in the projects. The purpose of this study is to propose the forecast model of deep excavation wall movements using artificial neural networks. The data of the Deep Excavation Wall Movements which were done form Long research is used of Artificial neural networks training and apply the real construction work measured data to the Artificial neural networks model. Applying the artificial neural networks to forecast the deep excavation wall movements can significantly contribute to identifying and preventing the accident in the overall construction work.

근접 깊은 굴착에서 천공장비에 의한 지반교란 특성 사례 연구 (Case Study of Ground Disturbance Characteristic due to Drilling Machine in Adjacent Deep Excavation)

  • 김성욱;한병원
    • 한국지반공학회:학술대회논문집
    • /
    • 한국지반공학회 2003년도 봄 학술발표회 논문집
    • /
    • pp.77-84
    • /
    • 2003
  • Deep excavations in the urban areas have been frequently going on in large scale. Soil-nailing and Earth-anchor supporting methods are generally used in deep excavation. These construction methods cause ground disturbances during drilling process, and damages of adjacent structures and ground due to the differential settlement throughout construction period, and unexpected behaviors of supporting system according to the characteristics of drilling machine and ground condition. This article introduces two actual examples of adjacent deep excavation for the construction of university buildings in granitic Seoul area. The important results of construction and measurements obtained using Crawler drilling machine for Soil-nailing and Earth-anchor supporting methods are summarized. And some suggestions are given to improve and develop the technique of design and construction in the deep excavation projects having similar ground condition and supporting method.

  • PDF

인공신경망기법을 이용한 굴착에 따른 지표침하평가 (Prediction of Deep Excavation-induced Ground surface movements using Artifical Neural Network)

  • 유충식;최병석
    • 한국지반공학회:학술대회논문집
    • /
    • 한국지반공학회 2003년도 봄 학술발표회 논문집
    • /
    • pp.69-76
    • /
    • 2003
  • This paper presents the prediction of deep excavation-induced ground surface movements using artifical neural network(ANN) technique, which is of prime importance in the perspective of damage assessment of adjacent buildings. A finite element model, which can realistically replicate deep excavation-induced ground movements was employed to perform a parametric study on deep excavations with emphasis on ground movements. The result of the finite element analysis formed a basis for the Arificial Neural Network(ANN) system development. It was shown that the developed ANN system can be effecting used for a first-order prediction of ground movements associated with deep-excavation.

  • PDF