Analiza ściśliwości warstwowanych iłów krakowieckich
Abstract
Analysis of compressibility of layered Krakowiec Clays.
A b s t r a c t. The substrate, whose compressibility has been analysed, served as subsoil for indirect foundations of bridges. A significant settlement of foundations was recorded while performing load tests. The results of the analysis indicate the specific structure of the Krakowiec Clays, as the cause of insufficient bearing capacity of piles. Small thickness of clay and silt layers prevents their separation, and certainly does not allow treating them as two soil types with different properties. The tested soil should be considered as a kind of natural composite, whose characteristics are unlikely to be "the resultant" of properties of constituent soils. Despite the high soil strength (very high values of strength parameters), the measured oedometer compression modules were significantly different from the standard attributed to this type of soils. The values of oedometer compression modules correspond with those prescribed by back analysis of settlement measured during the load test of piles. They were tested on natural undisturbed samples and on prepared samples of different humidities (from soil paste). The results were compared with those obtained by other researchers for soils of similar origin and alike physical properties.
A b s t r a c t. The substrate, whose compressibility has been analysed, served as subsoil for indirect foundations of bridges. A significant settlement of foundations was recorded while performing load tests. The results of the analysis indicate the specific structure of the Krakowiec Clays, as the cause of insufficient bearing capacity of piles. Small thickness of clay and silt layers prevents their separation, and certainly does not allow treating them as two soil types with different properties. The tested soil should be considered as a kind of natural composite, whose characteristics are unlikely to be "the resultant" of properties of constituent soils. Despite the high soil strength (very high values of strength parameters), the measured oedometer compression modules were significantly different from the standard attributed to this type of soils. The values of oedometer compression modules correspond with those prescribed by back analysis of settlement measured during the load test of piles. They were tested on natural undisturbed samples and on prepared samples of different humidities (from soil paste). The results were compared with those obtained by other researchers for soils of similar origin and alike physical properties.