Acting Governor DiFrancesco last week signed legislation requiring children who are 7 years old or younger and who weigh less than 80 pounds to be secured in child passenger restrain systems or booster seats.
Several studies focusing on injury prevention have shown a decline in injury rates with efforts such as smoke detector alarms, child restrain systems, speed limit and driver license laws, helmets, child safety caps, window guards to protect against falls and placement of pool fences [ 25, 33– 33].
This article presents an analytical model to predict the normal thrust force for the design of the restraining system of all-steel buckling-restrained brace (BRB) members.
A parametric study was conducted and showed that the restraining system can effectively reduce the seismic displacements of the bridge.
An external restraining system with steel piles is introduced under the main objective of the study, which is the enhancement of the earthquake resistance of seismically isolated bridges.
The external restraining system of the CWC-BRB is composed of two all-steel external tubes connected by either single or double sinusoidal corrugated webs.
The material utilization efficiency of the CSBRB is significantly improved compared with common BRB, since its cross-section spreads outwards by spacing two cores, thus improving the flexural rigidity of the restraining system.
A method to estimate the available restraining stiffness of a typical bolted all-steel BRB is presented and the internal actions in the restraining system resulting from the local buckling of the core are obtained through a simple and practical analysis.
Seven all-steel buckling-restrained braces (BRBs) were tested under cyclic loading to investigate the effect of the unbonding materials on the performance of BRBs, via the employment of a layer of 1-mm thick butyl rubber or pure air gap between the core plate and the restraining system.
Compared with existing models, the presented model accounts for the cyclic strain hardening behaviour of the BRB's steel core, the flexibility of the restraining system, the flow of frictional forces, the longitudinal variation of the core axial load and strain, and Poisson's effects on the core cross-section properties.
