Search results for " shear strength"

showing 3 items of 23 documents

La resistenza di interfaccia calcestruzzo poroso-terreni a grana fina per il consolidamento di pendii mediante trincee drenanti profonde

2022

Le trincee drenanti profonde rappresentano uno dei metodi più efficaci per la mitigazione del rischio da frana, in pendii con falda idrica. Esse sono realizzate mediante pannelli o pali secanti. Il riempimento è costituito di calcestruzzo poroso o materiale granulare. Se le trincee sono adeguatamente “innestate” nel terreno stabile e il materiale di riempimento ha sufficiente resistenza e rigidezza come il calcestruzzo poroso, si ha ulteriore in-cremento di resistenza a taglio per effetto shear keys, oltre a quello derivante dalla riduzione delle pressioni in-terstiziali. L’incremento di resistenza è dovuto sia alla resistenza all’interfaccia calcestruzzo–terreni sia a quella intrinseca del…

interface shear strengthPervious concreteSettore ICAR/07 - Geotecnicashear keys effect. Pervious concrete for deep trench drains used to stabilise slopes must simultaneously satisfy many requirements namely adequate hydraulic conductiv-ity adequate shear strength a few days after pour-ing capacity to act as a protective filter for soils in which the drain is installed good resistance to clog-ging and adequate residual hydraulic conductivity. The pervious concrete with appropriated mix-design can effectively satisfy all the abovementioned requirements. If the trenches depth is such that they intersect the sliding surface and if the trenches are adequate-ly "socket" in the layers of stable soil there is a fur-ther increase in shear strength due to the shear keys effect. This latter is in addition to the increase in shear strength resulting from the reduction of inter-stitial pressures that remains the principal scope of the draining trenches. Obviously the increase of shear strength due to the shear keys effect occurs if the trenches are filled with material that have enough strength and stiffness such as the porous concrete. In this case the beneficial effects of the draining trenches on stability are also due to the resistance at the concrete interface of the trench - soils and to the intrinsic resistance of the concrete at the area of the trench intersected by the sliding surface taken into consideration.The increase in resistance due to the shear keys effect can be very significant in relation to the thickness and interspace of the trenches. Results reported in the paper demonstrated that the interface fine grained soil-pervious concrete is higher than the residual shear strength of the soil.
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Validation of a Shear Model for RC and Hybrid Beams with Two Different Inclinations of Transversal Reinforcement

2016

The validation of an analytical model recently proposed for evaluation of the shear capacity in Reinforced Concrete (RC) beams containing multiple inclination of transverse stirrups is presented. The model is a suitable extension of that currently proposed in Eurocode 2 for the evaluation of the shear resistance, and it is derived by means of the the variable-inclination stressfield theory based on Nielsen’s plastic approach. Experimental and numerical data available in the literature on Hybrid Steel-Trussed Concrete Beams (HSTCBs) are used for model validation and result discussion. Finally, also the comparison with a different analytical approach for the assessment of the shear resistance…

reinforced concrete beamSettore ICAR/09 - Tecnica Delle Costruzionistress field approachprecast steel-concrete trussed beamstress field approach.analytical model; different inclined stirrups; precast steel-concrete trussed beams; reinforced concrete beams; shear strength; stress field approach.analytical modelshear strengthdifferent inclined stirrupdifferent inclined stirrupsprecast steel-concrete trussed beamsreinforced concrete beams
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An effective stress based shear strength criterion for unsaturated compacted double-porosity clays

2015

An effective stress based shear strength criterion is proposed taking into account the fundamental effects of microstructure characteristics on retention properties of compacted double-porosity clays and their overall coupled hydro-mechanical behaviour. Results of triaxial compression tests carried out on saturated and unsaturated samples of a compacted scaly clay show that points representative of failure conditions depict a unique failure envelope when the macropore degree of saturation is used in the definition of the effective stress and its evolution with the suction is taken into account. Furthermore, the proposed criterion is very effective to consider the most relevant aspects of su…

unsaturated soil effective stress shear strength microstructure
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