Dissertation > Excellent graduate degree dissertation topics show

The Influence of Pile Loading on Adjacent Existing Metro Tunnel Forces and Deformation

Author: HuangXiaoYang
Tutor: JiangQingQing
School: Central South University
Course: Underground space resources in science and engineering
Keywords: Pile foundation Pile top load Subway Tunnel Force state Deformation mode Governance measures MIDAS / GTS
CLC: TU473.1
Type: Master's thesis
Year: 2010
Downloads: 74
Quote: 0
Read: Download Dissertation

Abstract


Adversely affect the stability of the building will tunnel structure in subway along the perimeter of pile foundation. When the pile foundation load is gradually increased, the displacement of the soil around the pile will be extended to the tunnel at the impact of its force, caused by the the uneven displacement and cross-section of the tunnel structure convergence, resulting in the tunnel lining cracking seepage, Metro Rail tilt issues, thereby affecting the normal operation of the subway. Therefore, the study of pile foundation load on the existing subway tunnel is particularly important. In this paper, MIDAS / GTS finite element program, the establishment of a three-dimensional model to study the impact of the pile foundation load on the existing subway tunnel, consider a tunnel under a variety of influencing factors force and deformation characteristics, concluded the tunnel under the pile foundation load stress state of deformation modes, as well as governance measures. The details are as follows: 1. Study the Single Pile Top loads of stress and deformation of the tunnel, the existence of the tunnel on the pile foundation by the force and displacement field, considering the length of the pile, the pile diameter, pile top load the piles tunnel spacing, lining thickness, lining stiffness, cross-sectional form of parameter changes Tunnel maximum displacement variation and tunnel lining structure deformation characteristics. Study: ① tunneling stress field and tunnel lining structure stiffness of pile foundation lateral friction play and affect the displacement field. (2) with the pile length, pile diameter and pile top load increases, the displacement of the tunnel is also increased. Pile length and burial depth of the tunnel, when the pile long tunnel depth ratio of 1, the maximum displacement of the tunnel. With the increase in the spacing of the piles tunneling, the shift value of the tunnel gradually decreases exponentially. Lining thickness and stiffness of the greater, the smaller the maximum settlement, but the larger the minimum settlement. ③ tunnel on both sides of the pile overall sink, a large amount of increase in the maximum displacement, but the smaller the difference between the maximum displacement and minimum displacement. Settlement of circular cross-section to be slightly larger than the three heart-circular cross-section, but the settlement difference at the bottom to less than three hearts circular cross-section, so for the operational phase of the tunnel, the circular cross-section is better than the three hearts circular cross-section. ④ When the pile length is less than the tunnel depth, the maximum force point of the tunnel section between the arch back and arch entry, and with increasing pile length down; pile length is the minimum depth of the tunnel depth and tunnels between when the tunnel point of maximum force with increasing pile length and down; When the pile grew up in the lowest depth of the tunnel, with the length of the pile increase the maximum force point shift. Pile tunneling from the larger lower the largest force point of the tunnel. The top of the pile load is greater, the higher the position of maximum pressure. Simulation analysis of pile groups based on stress and deformation of subway tunnel under load, to consider the impact factors: piles tunnel spacing, pile spacing parallel to the tunnel direction perpendicular to the direction of the tunnel pile spacing, pile Rows etc., and also considering the longitudinal deformation of the tunnel. The the isolated pile masking effect simulation analysis obtained the state of isolation pile by the force of the tunnel, the magnitude of displacement and deformation characteristics of the impact, and consider the isolation pile length piles tunnel from the change of the masking effect of soil displacement. The study showed that: ① with the pile tunneling pitch increases, the displacement of the tunnel increasingly smaller, the rate of decrease of the displacement increasing pile tunneling spacing decreases. As the pile spacing parallel to the tunnel direction increases gradually decreases, the maximum displacement of the tunnel, and the rate of decrease is smaller. The pile spacing of the vertical direction to be smaller than the impact of the direction of the parallel tunnel pile spacing as the pitch increases, the displacement of the tunnel is reduced accordingly, but the rate of decrease is relatively small. ② tunnel longitudinal stiffness increases, the maximum settlement decreases vertical subsidence curve to flatten. (3) isolated pile can reduce the maximum displacement of the displacement of the top of the pile and the tunnel adjacent loaded piles, reducing the amount of 10% to 40%. Isolated pile of the tunnel cross-section of the point of maximum force deflects the difference can be reduced track settlement. The tunnel displacement decreases with increasing partition Piles long; tunnel displacement decreases rapidly when the partition the piles grew up in equal adjacent pile long. Greater than 1.25 times the length of the pile, cut off the blocking effect of the pile of soil displacement continue to increase, but the rate of increase is reduced. Pile tunnel away from the larger, the the tunnel displacement decreases the greater the percentage, the more obvious the effect of isolated pile; isolated pile from the Dutch pile group nearer the smaller the maximum displacement of the tunnel. 3 summarizes proposed tunnel cross-section the outside load deformation mode, summed up under the influence of several tunnels displacement control measures made supplements and amendments to two measures which, on this basis, the use of simulation analysis of this article concluded .

Related Dissertations

  1. Bearing Capacity of Cast-in-place Piles in the Karst Region of Yichun, Jiangxi,U213.1
  2. Experimental research of Beijing - Shanghai high-speed railway in deep soft soil section bridge foundation,U443.15
  3. Experimental Research on Liquefaction of Sands in Liaoxi Aeolian Area,TU441.4
  4. Many Kinds of Analysis Methods in Slope Stability Analyses and Appraisal Applied Research,TU43
  5. Simulation Study on Fire Diffusion of Subway Tunnel,U458.1
  6. Quantitative Study on Ultrasonic Evaluation of Flaws in the Concrete,TU375
  7. Experimental Study on the Mechanical Behaviors of Screw Pile under Inclined Load,TU473.1
  8. Simulation and Analysis on Pile Foundation of Bridge in Complex Geological Condition,U443.15
  9. Study on the Load Capacity Test Method of Extra-long Pile in the Middle and Lower Reaches of the Yellow River,U443.15
  10. Research on Bearing Caracteritic and Design Method of Rock-socketed Pile on Karst Region,TU473.1
  11. Numerical Simulation of Deformation Effect of Foundation Pit Excavation on Adjacent Buildings,TU753
  12. Study on the Ground Surface Deformation Laws Induced by Metro Shield Tunnel Construction,U455.43
  13. Numerical Analysis of Settlement Reducing Pile Foundation on Settlement Influence Factors and Optimum Design Methods,TU473.1
  14. Research on Marine Engineering Geology Characteristic and Feasibility of Pile Foundation at the Nanpu-Caofeidian Sea Area,P751
  15. Research on Engineering Geological Environment and the Suitability of Pile Foundation in Western Laizhou Bay,P75
  16. Assessment Index System Research and Application of Green Construction in Pile Foundation Engineering,TU753.3
  17. The Numerical Simulation Analysis about the Settlement Characteristics of Sparse Pile Foundation,TU473.1
  18. Analyzing the Influential Factors of the Pile Foundation Cost and Discussing the Method of Its Control and Management,TU723.3
  19. Yanji to Tumen Highway Tunnel Safety Assessment,U458
  20. Study on the Pile Supporting Capacity Character of Soft Soil Level Under Vertical Load in Guangzhou Area,TU473.1

CLC: > Industrial Technology > Building Science > Soil mechanics,foundation engineering > Foundation > Pile foundation and deep foundation > Pile
© 2012 www.DissertationTopic.Net  Mobile