scholarly journals Effect of Equivalent Load Distribution on the Accuracy of Mapping the Reinforcement Load Deflection Curve in LTP

2020 ◽  
Vol 10 (17) ◽  
pp. 6127
Author(s):  
Beata Gajewska ◽  
Marcin Gajewski

The formulations of tasks modelling embankments on soft soil, improved with columns and with reinforced load transfer platform (LTP), differ significantly. One of these differences is the distribution of equivalent load modelling part of the load carried by the LTP reinforcement and soft soil. This article analyses the influence of the nature of the load-modelling linear function, i.e., inverse triangular, uniformly distributed and triangular, as well as intermediate distributions. In total, 41 distributions of equivalent load were considered, and the results of the obtained deflection functions were compared with the measurement results of reinforcement deflection for 5 cases of experimental research available in the literature. A measure of the accuracy of mapping the reinforcement deflection curve was proposed as a relative error in relation to the deflection curve resulting from experimental measurements. Based on the analysis of the mapping error, it was determined that among the three commonly used distributions, the inverse triangular distribution shows the best fit in most of the analysed cases. However, not in every single case this is the distribution leading to a solution that best describes the behaviour of the geosynthetic reinforcement.

Large settlement associated with the construction of embankments on soft soil deposits is a challenging geotechnical problem that needs a special treatment. Reinforcing the embankments utilizing geosynthetics is an effective technique used to reduce the differential settlement, while the total settlement is unchanged. A more efficient technique is utilizing a combination between soft soil reinforcement using piles or rigid inclusions, thus increasing the equivalent stiffness of the entire soft soil stratum, and a load transfer layer reinforced by one or more layers of geosynthetics on top of the inclusions' head, in order to improve the load distribution process between the rigid elements. In this paper, the behavior of soft soil deposits reinforced with rigid inclusions is studied using three-dimensional finite element analysis, utilizing the "PLAXIS 3D 2020" software. Verification of the adopted modeling procedures is performed by the back analysis of a well-documented case study of a physical laboratory scaled model. Results of the numerical model showed a good agreement with the laboratory measurements in terms of both the settlement and load distribution aspects. Furthermore, results of both the developed numerical model and selected performed numerical analyses, from the literature, for the same case study, were compared showing better efficiency of the developed model compared to others and more consistency with the real behavior of the laboratory model. The verified model confirmed the efficiency of increasing the friction angle of the embankment on the load transfer mechanism between the rigid inclusions, and hence decreasing the resultant settlement.


2012 ◽  
Vol 594-597 ◽  
pp. 527-531
Author(s):  
Wan Qing Zhou ◽  
Shun Pei Ouyang

Based on the experimental study of rotary filling piles with large diameter subjected to axial load in deep soft soil, the bearing capacity behavior and load transfer mechanism were discussed. Results show that in deep soft soil foundation, the super–long piles behave as end-bearing frictional piles. The exertion of the shaft resistance is not synchronized. The upper layer of soil is exerted prior to the lower part of soil. Meanwhile, the exertion of shaft resistance is prior to the tip resistance. For the different soil and the different depth of the same layer of soil, shaft resistance is different.


2007 ◽  
Vol 11 (5) ◽  
pp. 545-552 ◽  
Author(s):  
Danielle D. Kleinhans ◽  
John J. Myers ◽  
Antonio Nanni

2018 ◽  
Vol 195 ◽  
pp. 03014
Author(s):  
Siswoko Adi Saputro ◽  
Agus Setyo Muntohar ◽  
Hung Jiun Liao

Excessive settlement due to consolidation can cause damage to the structure’s rest on soft soil. The settlement takes place in relatively longer. The preloading and prefabricated vertical drain (PVD) is often applied to accelerate the primary settlement. The issue in this research is the estimation of the settlement. The Asaoka method and the finite element method using PLAXIS-2D are used to estimate the final settlement of a PVD treated embankment. For the former, a complete record of the settlement was required; for the latter, some ground parameters are needed for the PLAXIS-2D analysis, such as the permeability of the soil. Because the installation process of PVD tends to influence the permeability of the in-situ soil around the PVD, the soil permeability after the installation of PVD needs to be adjusted. The numerical results were compared with actual settlement data to find out the best-fit input parameters (i.e. soil permeability) of the actual data. It was found that the best-fit soil permeability (k) used in the numerical study was about one-half of the k value determined from the laboratory test. The Root Mean Square Deviation shows that the settlement predicted by the numerical analysis has approximately 30% of the actual settlement.


2014 ◽  
Vol 587-589 ◽  
pp. 928-933 ◽  
Author(s):  
Feng Lian ◽  
Zhi Liu ◽  
Jie Xu ◽  
Qiang Wang ◽  
Xian Hu Hu ◽  
...  

Two experimental areas in a highway soft soil ground treatment project in Guangdong Province were designed to investigate the improvement mechanism of geogrid-reinforced and pile-supported embankment(GRPS).The experimental results showed: In End-bearing Pile Area,the differential settlement between pile and soil was bigger than that of Floating Pile Area,so the bearing capacity of soil was exerted to a certain extent in Floating Pile Area. The bearing efficacy of soil below the pile cap was little, so the replacement ratio of composite foundation could be calculated according to the pile cap dimension. The load transfer efficacy of the geogrid was better than that of the soil arch. Five kinds of methods were used to evaluate the soil arch in the fill and it was indicated that the results calculated by the BS8006 method and Carlsson method was close to the experimental data which was smaller than results calculated by Hewlett method and Terzaghi method, bigger than Guido method. Through the analysis of the pile-soil stress ratio, the improvement mechanism of the two types of GRPS were revealed.


2011 ◽  
Vol 189-193 ◽  
pp. 1132-1136 ◽  
Author(s):  
Yong Xu Zhao ◽  
Wen Jun Hu ◽  
Jun Mei ◽  
Niu Wei ◽  
Jian Jun Xie

After testing on T-type rubber bearing under tensile, compression and shear mechanical properties under different temperature in this paper. Obtained load deflection curve and destructive mode under different loading conditions at -40 and normal temperature of rubber components. Analysis the impact of temperature and the loading conditions that effect on load-elongation and destructive mode of T-type damping rubber structure. It showed that T-end rubber bearing has different kinds of deformation under different force-giving methods. Under compression, the stress pattern of the rubber bearing is three-dimensional and middle rubber bear the greatest force. Under tensile loading, the middle part of the rubber contract and the side with smaller lateral section has greater shrinkage; moreover, damage occurred in the area with stress concentration and weak strength. Under shearing action, extrude faces appeared with crinkle and damage occurred in the middle part of extrude faces. At the low temperature-40 , rubber support still has great elastic properties. The low temperature has a big effect on tensile properties and has little effect on damage properties.


1968 ◽  
Vol 41 (4) ◽  
pp. 977-987
Author(s):  
S. D. Gehman

Abstract The tire contour equation is derived for a flexible tire body with radial cords and a complete circumferential deflection, corresponding to the case of a radial-ply tire or a tire inflated inside a constraining cylinder. Equations are derived to calculate the load on a single cord in the deflected region using parameters of the un-deflected contour. It is then shown how the reasoning and equations can be generalized for a tire body with any cord path having a complete circumferential deflection so that the load-deflection curve for a single cord can be calculated. A new approximation method is described so that the integrals involved in these calculations can be evaluated in terms of incomplete elliptic integrals of the first and second kind with any desired accuracy. Finally, a procedure is given for summing cord loads in the usual spot deflection of a tire so that the load-deflection curve for a flexible tire body can be calculated from contour parameters of the undeflected tire. An illustrative calculation is included. Although the load-deflection curve for a single cord is convex toward the load axis, that for the tire is concave because more cords are involved as deflection progresses. A calculated contour does not exist beyond a limiting deflection, at which, presumably, buckling starts above the bead.


2013 ◽  
Vol 319 ◽  
pp. 409-413
Author(s):  
Jian Min Li

Different from the Slippage shipment, when using platform trailers for shipment, the structure’s weight evenly distributed on the small wheel’s axles, because of tire’s deformation, as the trailers continue moving to the barge, the surface contact between the wheels and ground makes the load gradually apply to the barge, then the center of gravity also changes. In this research, based on analysis of the heavy truck’s tire deflection curve, in the process of load distribution, method of calculating the structure’s weight on barge with the trailers gradually move forward can be obtained, through simulation analysis, the load adjustment can be ensured accurately.


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