Archives of Civil Engineering

This report describes the community involved in technology, organisation, and economics of theconstruction industry. The community includes mainly academics gathered around KILiW PAN, the Polish Academy of Sciences Section for Civil Engineering Projects. The results have been obtainedbased on the survey conducted in the period of 2007–2010. Some financial issues are presentedhere which influence the scope of the research underway and the didactic process. Some of theissues presented here comprise the subject matters of research, postgraduate studies, academicdegrees, as well as publications and international cooperation. Conclusions were presented in theform of suggestions in the field of research and teaching.

The article presents the application of finite element method for estimating settlements of road embankments founded on the soil reinforced with vertical drains and preloading method. The ideaof the method was the transition from the solution of one-dimensional consolidation proposed for two-dimensional solution, while maintaining the same consolidation time and comparison withresults obtained from measurements settlements of road embankment which is a part of planned Gdańsk Southern Ring Road near Przejazdowo site.

A multi-laminate constitutive model for soft soils incorporating structural anisotropy is presented. Stress induced anisotropy of strength, which is present in multi-laminate type constitutive models, is augmented by directionally distributed overconsolidation. The model is presented in theelastic-plastic version in order to simulate strength anisotropy of soft clayey soils and destructuration effects. Performance of the model is shown for some element tests and for the numericalsimulation of a trial road embankment constructed on soft clays at Haarajoki, Finland. The numerical calculations are completed with the commercial finite element code capable to performcoupled static/consolidation analysis of soils. Problems related to the initiation of in situ stress state, conditions of preconsolidation, as well as difficulties linked to estimation of the model parametersare discussed. Despite simple assumptions concerning field conditions and non-viscous formulationof the constitutive model, the obtained final results are of a sufficient accuracy for geotechnical practice.

Field investigations concerning screw piles and columns have been carried out for the “Bearing capacity and work in the soil of screw piles” research project, financed by the Polish Ministry of Science and Higher Education – project No N N506 369234. The tests of three instrumented screw piles were conducted together with CPTU tests and measurements of pile installation parameters (especially torque). The objectives of field investigations and the entire research project include discovering how screw piles work in the soil, locating and describing the correlations between CPTU results and rotation resistance during pile auger installation and next establishing correlations between CPTU results, rotation resistance and the bearing capacity of this kind of piles. The paper describes the investigation procedure and the basic results of tests carried out in the first of a series of sites.

Deep excavation walls can be analyzed and calculated by using classical methods (currently rarely in use due to their many simplifications) or numerical methods. Among the numerical methods we can distinguish a simplified approach, in which the interaction between soil and a wall structure is modelled by a system of elasto-plastic supports, and the finite-element method (FEM) in which the soil is modelled with mesh of elements. It is a common view that if we want to analyze only wall constructions, the first, simplified method of calculation is sufficient. The second method, FEM, is required if we want to further analyze the stress and strain states in the soil and the influence of the excavation on the surrounding area. However, as it is demonstrated in the paper, important differences may appear in the calculation results of both methods. Thus, the safety design of a deep excavation structure depends very much on the choice of calculating method.

The poorly cemented Ciężkowice poorly sorted sandstone and the compact Mucharz fine grain sandstone have been laboratory tested at the triaxial compressing conditions in thermo-pressurized chamber of a rigid press MTS-815. The confining pressure: P = σ₂ = gσ₃ range from 0 to 96 MPa and the temperature: T from 22°C to 120°C (simulated 500 m intervals from the surface to the depth of 3500 m). During (the) each test, the characteristics of deformation and the elastic wave velocity paths were simultaneously monitored. The volume density and longitudinal wave velocity showed a non-linear increase with the progress of simulated depth, a volume density growth by 1.6 to 4.0%, and the elastic wave velocity up to 250% of the primary value (surface condition), dependable on loading path, phase of deformation, and varying type of lithology. That may lead to wide error margin in a determination of rock’s engineering properties and also create discrepancies between the static parameters of rocks (Est, gνst) determined by standard laboratory load tests, and the dynamic parameters (Ed, νd) determined from the wave velocity and volume density.

The paper shows methods of analysis and assessment of partnering relations of construction enterprises with the use of questionnaires, statistics, and fuzzy logic. The results were obtained from Polish, Slovak and Ukrainian enterprises. The definition of partnering in the construction industry indicates that it is a qualitative concept. By applying a scale in the questionnaire, and due to mathematical analysis of the data, the final research result, showing the level of partnering relations of construction enterprises, is rendered quantitatively.

The fully coupled, porous solid-fluid dynamic field equations with u−p formulation are used in this paper to simulate pore fluid and solid skeleton responses. The present formulation uses physical damping, which dissipates energy by velocity proportional damping. The proposed damping model takes into account the interaction of pore fluid and solid skeleton.

The paper focuses on formulation and implementation of Time Discontinuous Galerkin (TDG) methods for soil dynamics in the case of fully saturated soil. This method uses both the displacements and velocities as basic unknowns and approximates them through piecewise linear functions which are continuous in space and discontinuous in time. This leads to stable and third-order accurate solution algorithms for ordinary differential equations. Numerical results using the time-discontinuous Galerkin FEM are compared with results using a conventional central difference, Houbolt, Wilson θ, HHT-α, and Newmark methods. This comparison reveals that the time-discontinuous Galerkin FEM is more stable and more accurate than these traditional methods.