Interakce pilotových základů s podložím

Abstract

This thesis focuses on the analysis of specific cases of models of foundation constructions. It features an analysis of the behavior of models of foundation constructions loaded by solitary force. It is an analysis of results of calculations, an analysis of results of measurement and their mutual comparison. The results of the measurements were gathered on specific models of foundation constructions, the results of calculations were gained by the most modern calculation programs. The thesis examines the behavior of models of pilots, foundation base and compound foundation. The above mentioned types of foundations were examined on the STAND device within the project of specific research SGS SP2014/47. The measurement was carried out on specific physical models in specific environment of the original foundation subsoil of tough clay. The experiments were carried out during 2014. Their aim was to verify the qualities of the subsoil in the location of tests and the behavior of various types of foundation constructions under load. The models of the foundation constructions were made of concrete class C16/20 and reinforced by rods B500B. The scale of the models was chosen due to the capacity and size of the testing device. The measurement was carried out on two models of pilots with diameter of 0.15 m and length of 0.85 m, while with one model; the influence of load capacity in the pilot base was eliminated. Two more models of foundation slabs were made. The slabs of square plan had sides of 0.6 m and height of 0.2 m. One of the slabs was a part of the compound foundation. All constructions were continuously loaded beyond the value of their load capacity. The loading proceeded in cycles of 5 min and 20 kN. The measurement of the pilot was terminated as soon as the pilot was pushed into the terrain. The loading of the slab and the compound foundation was terminated as soon as it was impossible to reach a higher pressure level in the hydraulic cylinder. Measurements of loading forces and horizontal deformations of objects and the adjacent terrain were carried out during the loading. The results were continuously automatically recorded. With theoretical analysis of behavior of foundation constructions, proper setting of limit conditions is always important. The calculations considered loading conditions from the own weight of the constructions and point loading by a solitary force. The loadings enter the calculations in their characteristic values without considering coefficients of loading, to make comparing with results of experimental measurements possible. Calculation models of foundation constructions MKP were modelled by the means of rod elements and board-wall elements. The solution applied theoretically derived relations and methods for solution of interaction between the foundation and subsoil. Mohr-Coulomb model was used for the foundation soil, concrete foundation elements were modelled as elastic, neglecting the material non-linearity. The sheathing friction was entered separately by a special sheath element. The results of the calculations are presented by graphic form for easier comparison with the values of the experimental measurement.