Estudo do efeito da inundação na variação de volume, na resistência de ponta e no módulo de elasticidade de um solo colapsível do Semiárido de Pernambuco

Abstract

Collapsible soils have a different hydromechanical when inundated. The paper analyzes the variation of volume, the point resistance and modulus of elasticity of a collapsible soil Petrolina due to wetting. The geotechnical investigation program developed field covers: reconnaissance boring wih SPT; collect undisturbed samples and deformed; tests with penetrometers static e dynamic DPL (Dynamic Light Petermeter); trials with Light Weight Deflectometer - LWD and test collapsibility with Expansocolapsômetro in natural and flooded soil. In laboratory tests were performed to the physical, chemical, microstructural characteristics and standard and double edometric testes to evaluate the soil collapsibility due to wetting. The soil is truly collapsible, has a structure with pores of simple packaging type and has a maximum collapse in the 160 kPa pressure. The collapse field smaller than that obtained in the laboratory and the time for the collapse process occurs is greater in the field. The results show that the elasticity modulus varies from 46.3 to 79.2 MPa and flooding causes a 88% these values. Since the modulus of elasticity obtained from LWD established a susceptibility criterion for collapsible soils thorough KLWD coefficient: high to KLWD> 4.20, low to KLWD <2.80 and average for KLWD between 2.80 and 4.20. There is good correlation between the deflection obtained with the LWD and displacements by blow obtained from the DPL, observing that when the deflection is low, the penetration rate is low, demonstrating greater stiffness of the soil.