The Whittier Narrows, California Earthquake of October 1, 1987—Damage to the I-5/I-605 Separator

1988 ◽  
Vol 4 (2) ◽  
pp. 389-405 ◽  
Author(s):  
M. J. N. Priestley
Keyword(s):  
Load Transfer ◽  
Lateral Load ◽  
Santa Ana ◽  
Working Stress ◽  
Shear Failures

The I-5/I-605 separator, a major nine span bridge, was severely damaged in the Whittier earthquakes. All columns of Bent 6, which is supported on the median strip of the Santa Ana Freeway (I-5) suffered shear failures, and the supported spans came close to collapse. Other minor damage included minor column hinging at more flexible bents, abutment pounding, and fracture of keeper plates at abutment rockers. Apparently much of this minor damage occurred during a major aftershock. Preliminary calculations indicate that the shear failures of Bent 6 resulted from disproportionate flexural and shear strengths of the columns, attributable to the working stress philosophy adopted in design, and the much greater stiffness of Bent 6 than adjacent bents. Movement joints with cable restrainers, at both ends of spans founded on Bent 6, make estimation of lateral load transfer from more flexible regions difficult.

scholarly journals Rollover Prevention System Dedicated to ATVs on Natural Ground

2012 ◽  
Vol 162 ◽  
pp. 505-514 ◽  
Author(s):  
Mathieu Richier ◽  
Roland Lenain ◽  
Benoit Thuilot ◽  
Christophe Debain
Keyword(s):  
Predictive Control ◽  
Control Algorithm ◽  
Load Transfer ◽  
Low Cost ◽  
Lateral Load ◽  
Dynamical Model ◽  
Rollover Prevention ◽  
Perception System ◽  
Prevention System ◽  
On Line

In this paper, an algorithm dedicated to light ATVs, which estimates and anticipates the rollover, is proposed. It is based on the on-line estimation of the Lateral Load Transfer (LLT), allowing the evaluation of dynamic instabilities. The LLT is computed thanks to a dynamical model split into two 2D projections. Relying on this representation and a low cost perception system, an observer is proposed to estimate on-line the terrain properties (grip conditions and slope), then allowing to deduce accurately the risk of instability. Associated to a predictive control algorithm, based on the extrapolation of riders action, the risk can be anticipated, enabling to warn the pilot and to consider the implementation of active actions.

A Numerical Investigation of Laterally Loaded Steel Fin Pile Foundations

2020 ◽  
Author(s):  
Te Pei ◽  
Tong Qiu ◽  
Jeffrey A. Laman
Keyword(s):  
Carrying Capacity ◽  
Load Transfer ◽  
Lateral Load ◽  
Steel Plates ◽  
Pile Foundations ◽  
Load Carrying Capacity ◽  
Element Analysis ◽  
Fea Model ◽  
Load Carrying ◽  
Maximum Improvement

Abstract The present study comprehensively evaluates the improvement in lateral load-carrying capacity of steel pipe piles by adding steel plates (fins) at grade level. This configuration of steel fin pile foundations (SFPFs) is effective for applications where high lateral loads are encountered and rapid pile installation is advantageous. An integrated finite element analysis (FEA) was conducted. The FEA utilized an Abaqus model, first developed to account for the nonlinear soil-pile interaction, and then calibrated and validated against well-documented experimental and filed tests in the literature. The validated FEA model was subsequently used to conduct a parametric study to understand the effect of fin geometry on the load transfer mechanism and the response of SFPFs subjected to lateral loading at pile head. The behavior of SFPFs at different displacement levels and load levels was studied. The effect of the relative density of soil on the performance of SFPFs was also investigated. Based on the numerical simulation results, the optimal fin width for maximum improvement in lateral load-carrying capacity was suggested and the underlining mechanism affecting the efficiency of fins was explained.

Nonlinear Active Rollover Prevention Control Strategies for a 5-Axle Tractor/Semitrailer

2001 ◽  
Author(s):  
A. Scott Lewis ◽  
Moustafa El-Gindy
Keyword(s):  
Active Control ◽  
Load Transfer ◽  
Sliding Mode ◽  
Control Strategies ◽  
Lateral Load ◽  
Lateral Acceleration ◽  
Computer Simulation Model ◽  
Parameter Uncertainties ◽  
Transfer Ratio ◽  
Vehicle Rollover

Abstract This paper presents new active control strategies to prevent heavy vehicle rollover and focuses mainly on cases of maneuver-induced rollover such as rollover in cornering and lane-change maneuvers. Two performance measures as control strategies are explored: the lateral load transfer ratio and the trailer lateral acceleration. A nonlinear 75,000 pound 5-axle tractor/semitrailer computer simulation model has been used to demonstrate the effectiveness of the proposed active control system. A new non-linear sliding mode controller has been designed and found to be effective in improving the dynamic performance and roll stability, regardless of parameter uncertainties, such as tires or suspension characteristics. The controller torque requirement is limited by the differential dynamic braking forces that the tractor drive axles are able to produce as a function of the applied dynamic loads and road surface condition. The results show that with this new controller, the vehicle lateral acceleration can be controlled to prevent rollover without significant change of the vehicle trajectory when active yaw torque is applied to the tractor drive axles. Also, simulation results indicate that the vehicle rollover might be prevented using either the lateral load transfer ratio or the lateral acceleration at the trailer centre of gravity as control strategies.

Consider Roll of Heavy Vehicle's Modeling Research

2013 ◽  
Vol 404 ◽  
pp. 250-256
Author(s):  
Rui Wang ◽  
Hao Zhang ◽  
Xian Sheng Li ◽  
Xue Lian Zheng ◽  
Yuan Yuan Ren
Keyword(s):  
Load Transfer ◽  
Lateral Load ◽  
Roll Angle ◽  
Force Analysis ◽  
Dynamics Model ◽  
Dynamic Variable ◽  
Positive Direction ◽  
Rollover Stability

Existed consider roll of heavy vehicle's dynamics model have defects and deficiencies. Vehicles lateral-load transfer that will lead to vehicles rollover is not considered; the whole vehicles dynamics model neglect unspring masss roll angle while the unspring masss independent force analysis considered the roll angel, the establishment of the model is not consistent in; the model dont have a united positive direction rule for all the variables. Because of all of these defects the model cant rightly reflect vehicles motion status. This paper takes lateral-load transfer as a dynamic variable; unspring masss roll angle is considered when establishing the whole vehicles dynamics model; all variables positive direction is united. Reasonable, right, applied to evaluate vehicle's rollover stability and quite newly model is established.

Testing Analysis on Load Transfer of Tractor-Semitrailer Steering and Braking

2014 ◽  
Vol 540 ◽  
pp. 164-169
Author(s):  
Hong Bo Gao ◽  
Hong Guo Xu ◽  
Hong Fei Liu ◽  
Cheng Zeng
Keyword(s):  
Simulation Model ◽  
Dynamic Simulation ◽  
Load Transfer ◽  
Lateral Load ◽  
Conventional Model ◽  
Longitudinal Load ◽  
Dynamic Simulation Model ◽  
Driving Stability

An algorithm about tractor-semitrailer longitudinal load and lateral load transfer amount was proposed in order to research the driving stability of tractor-semitrailer steering and braking. A dynamic simulation model of tractor-semitrailer including load transfer was established by using S-Function. The results show that the model including load transfer is more actual than conventional model to describe the driving stability of vehicle Further analyzed the effect of factors on load transfer when tractor-semitrailer steering and braking.

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