scholarly journals Numerical investigation of load transfer mechanisms in slopes reinforced with piles

2005 ◽  
Author(s):  
◽  
Eng-Chew Ang

The objective of the work is to use numerical analyses to evaluate the limit soil pressure on piles, to evaluate the load transfer mechanism, and to evaluate alternative means for estimating mobilized and limit loads on piles in piled-slope problems. It is found that limit forces predicted using 2-D, plane strain and 3-D analyses differ substantially. The computed limit force on piles in piled-slopes is sensitive to the interface roughness, pile spacing, modeling techniques, and constitutive model. For the 3-D model, which includes both the sliding and anchorage zones, the limit soil pressure calculated for the "flow" failure mode is approximately equal to that predicted by the Broms (1964) method. It is concluded that 2-D analyses of a horizontal slice is not suitable for evaluation of mobilized or limit lateral loads on piles. The 3-D mode analysis is a better method for modeling the actual piled-slope problems.

2009 ◽  
Vol 27 (4) ◽  
pp. 241-253 ◽  
Author(s):  
Ana Cristina C.F. Sieira ◽  
Denise M.S. Gerscovich ◽  
Alberto S.F.J. Sayão

Structures ◽  
2021 ◽  
Vol 31 ◽  
pp. 540-557
Author(s):  
Giosuè Boscato ◽  
Claudia Brito de Carvalho Bello ◽  
Antonella Cecchi

Author(s):  
Gang Zheng ◽  
Yawei Lei ◽  
Xuesong Cheng ◽  
Xiyuan Li ◽  
Ruozhan Wang

Collapses of braced or tied-back excavations have frequently occurred. However, the influence of the failure of some retaining structure members on the overall safety performance of a retaining system has not been studied. Model tests of failures of retaining piles, struts or anchors were conducted in this study, and the load transfer mechanisms underlying these conditions were analysed. When failures or large deformations occurred in certain piles, the increasing ratios of the bending moments in adjacent piles were much larger in the braced retaining system than in the cantilever system and more easily triggered progressive failure. When the strut elevation was lower or the excavation depth was greater, the degree of influence and range of pile failures became larger. When certain struts/anchors failed, their loads transferred to a few adjacent struts/anchors, possibly leading to further strut/anchor failure. The influence mechanisms of strut or anchor failure on piles were different from those of pile failure. As the number of failed struts or anchors increases, the bending moments of the piles in the failure zone first decrease and then increase to very high values. Therefore, the progressive failure path extends from struts/anchors to piles and will lead to large-scale collapse.


Author(s):  
Isotta Morfini ◽  
Luca Goglio ◽  
Giovanni Belingardi ◽  
Sayed A. Nassar

This study investigates the effect of cure time and surface roughness on mechanical performance of single lap joints (SLJ). Test joints are made of aluminum/aluminum or aluminum/magnesium adherends that are autoclave-bonded using a commercially available film adhesive. Joint mechanical performance is assessed in terms of the static load transfer capacity (LTC), fatigue life and failure mode. Except for the cure time, all the rates of the other autoclave-bonding parameters are kept constant; namely, the level of cure temperature and pressure, as well as the rates of autoclave heating, cooling, pressurization and depressurization. Test data, failure mode analysis, discussion, observations and conclusions are provided.


Géotechnique ◽  
2021 ◽  
pp. 1-39
Author(s):  
Huan Wang ◽  
M. Fraser Bransby ◽  
Barry M. Lehane ◽  
Lizhong Wang ◽  
Yi Hong

This paper presents a numerical investigation of the monotonic lateral response of large diameter monopiles in drained sand with configurations typical of those employed to support offshore wind turbines. Results from new centrifuge tests using instrumented monopiles in uniform dry sand deposits are first presented and used to illustrate the suitability of an advanced hypoplastic constitutive model to represent the sand in finite element analyses of the experiments. These analyses are then extended to examine the influence of pile diameter and loading eccentricity on the lateral response of rigid monopiles. The results show no dependency of suitably normalized lateral load transfer curves on the pile diameter and loading eccentricity. It is also shown that, in a given uniform sand, the profile with depth of net soil pressure at ultimate lateral capacity is independent of the pile diameter because of the insensitivity of the depth to the rotation centre for a rigid pile. A normalization method is subsequently proposed which unifies the load-deflection responses of different diameter rigid piles at a given load eccentricity.


2007 ◽  
Vol 345-346 ◽  
pp. 673-676
Author(s):  
Jong Duk Chung ◽  
Jang Sik Pyun

Engineering safety diagnosis of crashed subway electric multiple units (EMUs) was conducted for safety assessment. Several advanced engineering analysis techniques including nondestructive evaluation (NDE) techniques and stress and structural analyses programs, were performed for better understandings and exploration of failure analysis and safety concerns. Moreover, stress and structural analyses using commercial I-DEAS software provided important information on stress distribution and load transfer mechanisms as well as the amount of damages during the crash. One-dimensional crashworthiness was conducted to estimate the speed at the time of the accident by investigating the permanent deformation of the train. The estimated speed was used as the input value of a three-dimensional crashworthiness analysis. A good agreement has been found between structural analysis results and the results of actual damages in EMUs during crash. In this investigation, various advanced engineering analysis techniques for the safety analysis of subway EMUs have been introduced and the analysis results have been used to provide the critical information for the safety assessment of crashed EMUs.


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