Analysis of Excavation-induced Deformation with Different Soil Models
Abstract: The monitored case of deep excavation works located in the centre of Warsaw is described and back analysed as a boundary value problem with the finite element method. The excavation was carried out in over-consolidated clayey layers under the support of braced diaphragm walls. Accurate simulation of such soil-structure interaction problems requires advanced soil constitutive models – especially for the pre-failure range of small strains. On the other hand, such models should not be very complex and their material parameters should be relatively simple to obtain from laboratory and in situ surveys. By means of a case study, this paper examines several simple elasto-plastic constitutive models for the simulation of the behaviour of soil layers. The influence of such characteristics of the soil behaviour, as anisotropy and non-linearity of stiffness, is studied in the paper. The discussion concerns the problems related to the application of the models for a practical example. The comparison is focused on the obtained and measured displacements of the neighbouring building and diaphragm walls.
An experimentally based "bubble' model for clay
In order to extend the Cam clay model an inner kinematically hardening bubble is added in order to match experimentally observed hysteretic response. The new model is found to be quite successful in reproducing patterns of response observed in slow cyclic oedometer and triaxial tests. -from Authors
The Intuitive Physics of the Equilibrium of the Lever and of the Hydraulic Pressures: Implications for the Teaching of Elementary Physics.
The research field of intuitive physics focuses on discrepancies between 
theoretical and intuitive physical knowledge. Consideration of these 
discrepancies can help in the teaching of elementary physics. However, 
evidence shows that theoretical and intuitive physical knowledge may also 
be congruent. Physics teaching could further benefit from understanding the 
reasons for this congruence. The present study explored these reasons by 
investigating the intuitive physics of the equilibrium of the lever and of the 
hydraulic pressures. It was found that the intuitive-physics law of the lever 
was multiplicative for all participants while the intuitive-physics law of the 
hydraulic pressures differed among participants. Since these laws are 
equally simple and the layman probably has had extensive experience with 
the lever and scarce or no experience with the hydraulic lift, these findings 
support the general hypothesis that physical laws and corresponding 
intuitive-physics laws are congruent when people have had experience with 
the respective phenomena. The results and theoretical considerations suggest 
two strategic principles for teaching elementary physics.