The paper presents theoretical basis for the construction of local empirical relationships and so-called “interrelationships” from CPTU, SCPTU, SDMT tests and VT (vane test). There are also examples of correlations for overconsolidated and normally consolidated sediments from the group of “transition” soils from the area of Poland. The second part of the paper is dedicated to the use of CPTU and DMT methods in separation of homogenous layers of the subsoil, in the context of stratigraphy, rules are given for construction of model 1-D, 2-D and 3-D quasi. The paper also contains examples and comments on the theoretical basis for the construction of stiffness models of the subsoil in 2-D and quasi-3-D. For the construction of the models, constrained modulus which corresponds to the oedometric modulus was used. The values of this module were determined from the characteristics of penetration from CPTU and DMT tests.
ON SOME ISSUES OF CHARACTERISTIC VALUES EVALUATIONS IN GEOTECHNICS
Autor
Wojciech Puła
Pages
21–26
Keywords
Eurocode 7, coefficient of variation, random field, fluctuation scale, variance reduction function
Abstract
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The paper presents various possibilities of evaluating characteristic values of soil properties in the context of Eurocode 7 recommendations. Some simplest approaches have been illustrated by computing and comparing resulting of characteristic values. Next the very basic concepts of random fields and spatial averaging were introduced. Consecutively, as application, the Schneider method has been demonstrated and applied to bearing capacity problem incorporating Prandtl’s mechanism. The obtained results were compared with evaluation based on spatial averaging along slip lines (in Prandtl’s mechanism). It appears that random field approach in conjunction with Schneider’s method gave satisfactory results considering Eurocode 7 requirements. It has been pointed out that probabilistic approach in selecting parameters for geotechnical design plays a vital role in safety evaluation.
2D-models of multilayered plates are usually derived by a discretization approach across the plate thickness. Every discretized element coincides with a homogeneous layer of the medium and basic unknowns are assumed to be temperature and/or displacement fields on the plate interfaces. If the number of homogeneous layers is large then the discretization approach leads to a large number of basic unknowns. In this contribution there is proposed a new approach to the 2D-modelling of heat conduction which results in 2D-model equations for only two basic unknowns, independently of the number of layers.
In the paper selected calculations methods of foundations settlements and the conditions based on Eurocode 7 in the range of checking serviceability limit state are presented.
SELECTED ISSUES CONNECTED WITH CHOOSING PARAMETERS AND VERIFYING ULTIMATE BEARING CAPACITY LIMIT STATES
Autor
Joanna Bzówka
Pages
55–72
Keywords
Eurocode 7, ultimate bearing capacity limit states, characteristic and computational values of geotechnical parameters, partial factors, FEM
Abstract
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In the paper selected issues connected with choosing parameters and verifying ultimate bearing capacity limit states are presented. The range of paper subject was divided into three following parts: analysis of bearing capacity of pad foundation, stability assessment and ultimate limit HYD states which are based on Eurocode 7.
SELECTED STANDARDS IN EVALUATION OF GEOTECHNICAL PARAMETERS DERIVED FROM LABORATORY TESTS
Autor
Mirosław J. Lipiński, Małgorzata Wdowska
Pages
73–89
Keywords
laboratory tests, test procedures, shear strength, stiffness
Abstract
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In the last period of progress in geotechnical engineering in Poland, some existing standards concerning evaluation of soil parameters as well as interpretation of laboratory tests results can be observed. A concise characteristic of these standards including rational of their existence is presented in the paper. Next, attention was drawn to the most important aspects of laboratory tests determining the test results. The most popular method for evaluation of sample quality was shown with use of deep subsoil example. The most important factors affecting test quality were also presented. Reference was made to interpretation of shear strength results as well as to evaluation of stiffness accounting for strain range and stress level.
EXAMINATIONS BUILDING TECHNOLOGY OF MULTI-OCCUPIED BUILDINGS
Autor
Anna Sobotka, Aleksandra Radziejowska
Pages
91–106
Keywords
residential buildings, building technologies, evaluation of AHP
Abstract
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Residential construction in Poland are mostly multi-family houses built in different technologies depending on the region, the local resource base and offer manufacturers of building materials. The article shows the results of offers from different developers on current real estate market in the Cracow and Lublin region. Through the surveys, as well as statistical data derived from the Central Statistical Office, the paper presents the types of technologies that are currently used in residential construction. The comparative assessment was performed after extract of the two most used technologies of erect multifamily buildings with multi-criteria AHP analysis. In the light of the adopted criteria, the two most commonly technology were analyzed. Improved traditional technology has proven to be better, as shown in figure matrix GSM. It can be seen that the results of the comparative analysis performed confirmed technology trends of the housing market today.
This paper presents the design of prototypes, methods of testing and analysis of the strength of concrete beams reinforced with rebar connections. To determine the characteristics of strength, deformation and fracture of experimental beams were tested to complete re-fracture. It is shown that it is possible to restore the strength of reinforced concrete beam by 77–90% by treatment with modern injection materials and technologies.
For reinforcement of prestressed concrete structures using reinforced thermohardened steel rebar standard length 12 m class A400, A500, A600, A800 with periodic profile. However, thermo-hardened steel rebar is essential for the production flaw – bad soldered, welded connection to that she did not meet the performance requirements for fittings in this class. Since adhesion to concrete reinforcement studied mainly experimental method because the results depend on many factors. This paper presents the design of prototypes, methods of testing and analysis of the strength of concrete beams reinforced with connected valves. Experimental research program provides four series test reinforced concrete beams crossing 120 × 220 mm length 2000 mm bend with two concentrated forces. Experimental beams were reinforced with welded frame constructions of armature 4 ∅ 8 A400 and working pre-stressed armature ∅ 12 A500C. Steel bars in reinforced concrete beams connected by crimp sleeves. To determine the characteristics of strength, deformation and crack-resisting of experimental beams they were tested for bending to destruction.