• Title/Summary/Keyword: settlement profile

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A displacement controlled method for evaluating ground settlement induced by excavation in clay

  • Qian, Jiangu;Tong, Yuanmeng;Mu, Linlong;Lu, Qi;Zhao, Hequan
    • Geomechanics and Engineering
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    • v.20 no.4
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    • pp.275-285
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    • 2020
  • Excavation usually induces considerable ground settlement in soft ground, which may result in damage of adjacent buildings. Generally, the settlement is predicted through elastic-plastic finite element method and empirical method with defects. In this paper, an analytical solution for predicting ground settlement induced by excavation is developed based on the definition of three basic modes of wall displacement: T mode, R mode and P model. A separation variable method is employed to solve the problem based on elastic theory. The solution is validated by comparing the results from the analytical method with the results from finite element method(FEM) and existing measured data. Good agreement is obtained. The results show that T mode and R mode will result in a downward-sloping ground settlement profile. The P mode will result in a concave-type ground settlement profile.

Accurate Estimation of Settlement Profile Behind Excavation Using Conditional Merging Technique (조건부 합성 기법을 이용한 굴착 배면 침하량 분포의 정밀 산정)

  • Kim, Taesik;Jung, Young-Hoon
    • Journal of the Korean GEO-environmental Society
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    • v.17 no.8
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    • pp.39-44
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    • 2016
  • Ground deformation around construction site in urban area where typically adjacent structures are located needs to be strictly controlled. Accordingly, it is very important to precisely monitor the ground deformation. Settlement beacon is typically employed to measure the ground deformation, but meanwhile the rapid development in electronic technology enables 3D image scanner to become available for measuring the ground deformation profile in usual construction sites. With respect to the profile measurement, the 3D scanner has an advantage, whereas its accuracy is somewhat limited because it does not measure the displacement directly. In this paper, we developed a conditional merging technique to combine the ground displacement measured from settlement beacon and the profile measured by the 3D scanner. Synthetic ground deformation profile was generated to validate the proposed technique. It is found that the ground deformation measurement error can be reduced significantly via the conditional merging technique.

The Determination of settlement boundary for the rock filled embankment using seismic geotomography (탄성파 토모그래피 기법을 이용한 제방의 사석침하 평가)

  • Won, Kyoung-Sik;Park, Chung-Hwa;Jeong, Baek;Park, Sang-Uk
    • The Journal of Engineering Geology
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    • v.12 no.1
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    • pp.89-93
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    • 2002
  • Seismic geotomography method was performed to verify rock-filled settlement and its stability in No.38+0 profile and No.40+0 profile. The velocity distributions of geotomography method expressed the quantitative value of the ground conditions. The rock-filled layer and in-situ sediments layer are clearly divided on the basis of seismic velocity 2100 m/sec which is derived from the results of seismic geotomography and boring. Current rock-filled settlement conditions are somewhat different from designed settlement estimation line. Seismic geotomography represents current settlement conditions as a quantitative analysis.

Longitudinal Deformation Profile in Tunnel using Measured Data (계측자료를 이용한 터널의 종단변형도)

  • Jang, Won-Yil;Yang, Hyung-Sik;Chung, So-Keul
    • Tunnel and Underground Space
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    • v.18 no.5
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    • pp.338-342
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    • 2008
  • Longitudinal deformation profile(LDP) has been obtained mostly by numerical analysis. In this study, LDP was plotted by measured data from horizontal inclinometer and crown settlement. Deformation of foe ahead was determined by comparing to the maximum deformation point and deformation of after excavation was determined by regression of the measured crown settlement data. The result shows that crown deformation began as f3r as 3D ahead of the face. Crown settlement at the face was 40% of ultimate deformation, which was 10% higher than numerical results, and the deformation converged after excavation of 4D.

Elastic settlements of identical angular footings in close proximity

  • R. Sarvesha;V. Srinivasan;Anjan Patelb
    • Geomechanics and Engineering
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    • v.32 no.2
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    • pp.193-207
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    • 2023
  • In general, the numerous classical approaches available in the literature can anticipate the settlement of shallow foundations. As long as the footings are not in close proximity to other subsurface buildings, the findings achieved using these methods are legitimate and acceptable. However, due to increased urbanisation and land scarcity, footings are frequently built close together. As a result, these footings' settlement behaviour differs from those of isolated footings. A simpler approach for assessing the settlement behaviour of two square or rectangular footings placed in close proximity is presented in this work. A Parametric study has been carried out to examine the interference effect on the settlement of these footings placed in close vicinity on the surface of a homogeneous, isotropic and elastic soil medium. The interaction factors are examined by varying the different aspect ratios (L/B), clear spacing ratio (S/B) and intensity of loading on the right footing with respect to the left footing. Further, variation of the settlement ratio (δ/B) with respect to embedment depth ratio Df/B is examined. For square and rectangular footings, the interference settlement profile is also investigated by varying the clear spacing ratio (S/B) and the degree of loading. The results were compared to 3D finite element analysis and experimental data that were available.

A study on ground surface settlement due to groundwater drawdown during tunnelling (터널 굴착시 지하수 저하로 인한 지반침하에 관한 연구)

  • Yoo, Chung-Sik;Kim, Sun-Bin
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.9 no.4
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    • pp.361-375
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    • 2007
  • This paper presents the results of investigation on tunnelling-induced ground surface settlement characteristics in water bearing ground using finite element (FE) stress-pore pressure coupled analysis. Fundamental interaction mechanism of ground and groundwater lowering was first examined and a number of influencing factors on the results of the coupled FE analysis were identified. A parametric study was then conducted on the influencing factors such as rock type, thickness of soil layer, permeability of shotcrete lining, among others. The results indicate that the tunneling-induced groundwater drawdown results in a deeper and wider settlement trough than without groundwater drawdown, and that the Error function approach does not yield satisfactory result in predicting a settlement profile. The results of analysis are summarized so that the relationship between the settlement and the influencing factors can be identified.

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Experimental and finite element analyses of footings of varying shapes on sand

  • Anil, Ozgur;Akbas, S. Oguzhan;Babagiray, Salih;Gel, A. Cem;Durucan, Cengizhan
    • Geomechanics and Engineering
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    • v.12 no.2
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    • pp.223-238
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    • 2017
  • In this study, bearing capacities and settlement profiles of six irregularly shaped footings located on sand have been experimentally and analytically investigated under the effect of axial loading. The main variable considered in the study was the geometry of the footings. The axial loads were applied from the center of gravities of the test specimens. Consequently, the effect of footing shape on the variation of the bearing capacities and settlement profiles have been investigated in this paper. The three dimensional finite element analyses of the test specimens were conducted using the PLAXIS 3D software. The finite element model results are in acceptable agreement with the results obtained using experimental investigation. In addition, the usability of the finite element technique by design engineers to determine the bearing capacities and settlement profiles of irregularly shaped footings was investigated. From the results of the study, it was observed that the geometric properties of the footings significantly influenced the variation of the bearing capacities and settlement profiles.

Time dependent behavior of piled raft foundation in clayey soil

  • Fattah, Mohammed Y.;Al-Mosawi, Mosa J.;Al-Zayadi, Abbas A.O.
    • Geomechanics and Engineering
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    • v.5 no.1
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    • pp.17-36
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    • 2013
  • Settlement of the piled raft can be estimated even after years of completing the construction of any structure over the foundation. This study is devoted to carry out numerical analysis by the finite element method of the consolidation settlement of piled rafts over clayey soils and detecting the dissipation of excess pore water pressure and its effect on bearing capacity of piled raft foundations. The ABAQUS computer program is used as a finite element tool and the soil is represented by the modified Drucker-Prager/cap model. Five different configurations of pile groups are simulated in the finite element analysis. It was found that the settlement beneath the piled raft foundation resulted from the dissipation of excess pore water pressure considerably affects the final settlement of the foundation, and enough attention should be paid to settlement variation with time. The settlement behavior of unpiled raft shows bowl shaped settlement profile with maximum at the center. The degree of curvature of the raft under vertical load increases with the decrease of the raft thickness. For the same vertical load, the differential settlement of raft of ($10{\times}10m$) size decreases by more than 90% when the raft thickness increased from 0.75 m to 1.5 m. The average load carried by piles depends on the number of piles in the group. The groups of ($2{\times}1$, $3{\times}1$, $2{\times}2$, $3{\times}2$, and $3{\times}3$) piles were found to carry about 24%, 32%, 42%, 58%, and 79% of the total vertical load. The distribution of load between piles becomes more uniform with the increase of raft thickness.

A Study on the Operation of SURF in the Bolero System (볼레로 시스템상의 SURF의 운영에 관한 연구)

  • Jeon, Soon-Hwan
    • The Journal of Information Technology
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    • v.6 no.4
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    • pp.163-175
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    • 2003
  • SURF is a compliance engine, checking document content against detail in an established agreement. It provides a single vehicle for handling documentary trade settlement, regardless of the risk profile and financing requirements of the parties involved. That is, SURF, a Value Added Service connected to the Core Messaging Platform, is a documentary trade settlement service. It offers users of the system automated document compliance checking and a tool to manage the workflow in connection with documentary trade settlement. The Service supports varying degrees of risk transfer between buyer, sellers and banks and supports transactions from open account to more complex Letters of Credit.

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Review on Data Acquisition of Renewable Power Generators (신재생발전기의 데이터 취득방안에 대한 고찰)

  • Lee, Bong-Kil;Kim, Wan-Hong;Choi, Joon-Ho
    • Journal of the Korean Solar Energy Society
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    • v.40 no.3
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    • pp.1-20
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    • 2020
  • In accordance with the Government's policy, renewable power generation is expanding very largely. This leads to increasing uncertainty in the power market and power system owing to the intermittent and fluctuating output characteristics of renewable power generators. Data on the acquisition of renewable power generators can be largely classified according to the operation of the power market and power system. Data on the settlement for the payment for the power amount are acquired in the power market, and real-time data for monitoring the status and output of the generators are acquired in the power system. However, renewable power generators operating in the power market have different acquisition cycles depending on the method of communication of the power meter. They acquire data only for settlement purposes and have no real-time data, which requires improvement. In this paper, the acquisition status is reviewed by classifying the data of renewable power generators into settlement and real-time data. In addition, measures and acquisition criteria for real-time data of renewable power generators for improving the acquisition method are proposed.