Energy Method Solution for the Vertical Deformation of Longitudinally Coupled Prefabricated Slab Track

Abstract

Upwarping on the longitudinally coupled prefabricated slab track system caused by the rising temperature is a common distress, which deteriorates the mechanical properties of the coupled slabs and the vertical stability of slabs. The objective of this paper is to quantify the upwarping deformation on the slab subjected to temperature force and to find out the influence of different factors on the upwarping phenomenon of the slabs. An analytical expression is deduced using energy method, and a finite element model is also established to verify the analytical solution's adequacy. The following main findings are drawn: (1) when the amplitude of the initial elastic misalignment is equal to a half of the amplitude of the initial plastic misalignment and the half-wavelength min takes the most unfavorable value, the maximum relative error between the analytical solution and the result in FEM is only 2.64%, which demonstrates that the analytical solution correlates well with the FEM results.(2) min is closely related with . With the increase of , min becomes longer, and the maximum length of the half-wavelength is 7.769 m.(3) When the total amplitude + exaggerates, the slab will be much likely to suffer upwarping.

Identification of Temperature-Induced Deformation for HSR Slab Track Using Track Geometry Measurement Data

“…It was found by Zhu and Cai [6] that the temperature difference between the top and bottom surfaces of track slab can reach over 16 • C. The temperature gradient load induced by the great temperature differential may result in the generation of pulling and curling stresses in the prefabricated concrete slabs [32] and structural defects. Typical temperature-induced slab track defects include interface debonding/delamination between CA mortar and track slab [4,7,12,18,25,26,32,39], decreased compressive strength, cracking and damage of CA mortar [9,15,16,33,35,[40][41][42], wide and narrow juncture defects [8], warping deformation of track slab [13,16,26,38], etc.…”

“…Among these track defects, warping deformation of slabs ( Figure 1) attracts much attention from HSR operators as it can not only deteriorate the mechanical properties of slab track but also influence the geometric condition of slab track [16]. Warping deformation starts with initial misalignment/upward curl during the construction phase and usually occurs during high-temperature seasons [16]. Under the aforementioned temperature effect, the top surface of slabs will elongate, while the bottom will compress [16,20,26,39].…”

“…Warping deformation starts with initial misalignment/upward curl during the construction phase and usually occurs during high-temperature seasons [16]. Under the aforementioned temperature effect, the top surface of slabs will elongate, while the bottom will compress [16,20,26,39]. As a result, slab warps upward due to eccentric compression.…”

“…To investigate how track slab damages initiate and how they affect vehicle-track system dynamics and track irregularities, previous studies carried out numerical simulations [3][4][5][6][7][8][10][11][12][13][14][15][16], full-scale tests [9,[17][18][19], and field tests [15,20,21]. These studies shed some light on repair works for defects, slab maintenance, and life-cycle management of slab track.…”

Analytical Model Tracing Deformations in Multistorey Large Timber Panel Building

“…Deformations appearing as a result of loading and of altering the moisture content in wood must not exceed the limit values, taking into account the possibility of failures of internal finishes and considering also the functional and aesthetic requirements. Closure of fissures (clearance) in the timber element connections under compression stress also causes the increase of deformations (Basta et al, 2012;Dong & Sun, 2017;Ren, Deng, Jin, Yang, & Liu, 2017). As it comes from literature review the main source of vertical deformation in the wood framed buildings has been examined as a result of wood shrinkage.…”