This paper describes a series of analyses carried out using the commercial finite element package, DIANA, to analyse three different types of reinforced concrete continuous two span deep beams, S1, S2 and S3. The spans were each of 1340mm the depth of the beam 650mm and the width 90mm, the difference between the three types of beam was in the reinforcement patterns. Test results obtained over a number of years for nominally identical beams were available, six results for S1, 2 for S2 and 5 for S3. The tests were carried out at the University of Cambridge, and the non-linear finite element analysis by a separate team at Heriot-Watt University. The data provided for the analysis was the geometric data for the beams, the reinforcement patterns and the yield strength of the reinforcement and the cube strength and tensile strength of the concrete. Also provided was the loading arrangement used in the tests. No further communications about the experiments was permitted. The beams were analysed and on completion results compared with the experimental data. No subsequent analyses have been carried out although after inspection of the experimental data various ‘improvements’ that could be implemented in the analyses were noted. Whilst the analyses were carried out using DIANA, the conclusions apply to any non-linear reinforced concrete finite element analysis. I. M. May, Department of Civil and Offshore Engineering, Heriot-Watt University, Edinburgh, UK C. T. Morley, Department of Engineering, University of Cambridge, Cambridge, UK Y. Y. Chen, Department of Civil and Offshore Engineering, Heriot-Watt University, Edinburgh, UK
This paper investigates the stepping frequency and velocity of people walking. It considers 800 measurements on two footbridges and two shopping floors. During the measurements, the participants were not aware that they were being observed and walked naturally. The measurements of walking frequency, velocity and step-length were processed using statistical methods and the stepping frequency and velocity of the walking determined. It is found that (a) on shopping floors the people walk with an average frequency of 2.0Hz and a velocity of 1.4m/s, but on the footbridges they walk with an average frequency of 1.8Hz and a velocity of 1.3m/s; (b) the step-length on the shopping floors and the footbridges are almost the same with average values of 0.75m for men and 0.67m for women; (c) the men walk with a higher velocity than the women, while the women walk with higher frequency than the men; and (d) there is a linear relationship between walking velocity and frequency which is different for men and women. The results are compared with data obtained approximately 20 years ago. Aikaterini Pachi, BEng, MSc Ktiriodomiki, Volos, Greece Tianjian Ji, BSc MSc, PhD, CEng, MIStructE Senior Lecturer, School of Mechanical, Aerospace and Civil Engineering, The University of Manchester
Horizontal axis wind turbines are dynamic structures. The foundations available to support these machines are varied, and the choice of foundation type has several influencing factors. The loading transmitted to the foundation is dependant on the power regulation philosophy of the turbine, the wind climate of the region where the turbine is to be installed, and the physical characteristics of the machine. The relationship between the frequently occurring loads and the extreme loads is discussed, with an explanation of how this bears on foundation design. Foundation design may also be impacted by additional factors such as no uplift criteria, ground sensitivity to cyclic loading and foundation stiffness requirements. The stiffness of deep water offshore foundations is investigated, with reference to study data. The paper concludes by comparing ULS and ALS load factors recommended by design codes. Danny Bonnett MA, CEng, MICE Design Civil Engineer, RES Group, Beaufort Court, Egg Farm Lane, Kings Langley, Hertfordshire. WD4 8LR