Author: Pearce, P T
N/A
Standard: £10 + VATMembers/Subscribers: Free
Members/Subscribers, log in to access
Pearce, P T
The Structural Engineer, Volume 75, Issue 1, 1997
Changing social needs, upgrading of design standards, increased safety requirements, continual upgrading of service loads, the increase in the volume of traffic and chloride-induced deterioration means that thousands of bridges need repair or reconstruction. Based on recent bridge management statistics, 83 800 reinforced and prestressed concrete bridges in the EU require maintenance, repairs and strengthening with an annual budget of £215M, excluding traffic delay and management costs. This problem is not confined only to the EU. Based on US Government statistics, of the total number of bridges in the USA over 250 000 are in need of improvement. Governments across the wdrld are looking for new technologies and cost-effective solutions. J.S. Lane, M.B. Leeming and P.S. Fahole-Luke One of the methods
According to conventional earthquake resistance strategy, most structures are considered fixed to the ground at their footings. Therefore, when an earthquake occurs, its seismic waves can transmit in an unimpeded manner throughout the structure, causing forced vibrations in the superstructure. Under these circumstances the dynamic behaviour of the structure can magnify the response to ground movements caused by the quake. Professor T.-Q. Song and Professor W.-J. Wang
This paper describes the analysis of large scaffold structures by 2- and 3-dimensional models. The models have semi-rigid joints between scaffold members. A prototype structure was analysed and the results were compared with test data from Stuttgart. Both 2- and 3-dimensional analyses gave good correlation. The basic scaffold, 30m high x 20m wide, given in BS 1139 was then analysed. The 2-dimensional models gave excessive displacements and subjected the windward standard to uplift forces. A 3-dimensional model with small joint stiffhesses showed the beneficial effects of interactions between the front and rear faces of the scaffold in producing acceptable results. M.H.R. Godley and R.G. Beale