Laboratory and field evaluation of modulus-suction-moisture relationship for a silty sand subgrade

Autor: Susit Chaiprakaikeow, Auckpath Sawangsuriya, Rizki Maretia Novi Barus, Apiniti Jotisankasa
Rok vydání: 2019
Předmět:
Zdroj: Transportation Geotechnics. 19:126-134
ISSN: 2214-3912
DOI: 10.1016/j.trgeo.2019.03.005
Popis: A change in soil modulus in response to suction-moisture variation after compaction plays a vital role on modulus-based compaction control during earthwork construction. This study investigated the small-strain modulus-suction-moisture relationship for a silty sand subgrade using the laboratory free-free resonant frequency (FFR) and the in-situ spectral analysis of surface waves (SASW) in a trial section of highway construction project in Thailand. The post-compaction soil water retention curves (SWRCs) at different compaction states were investigated over the entire range of suction. Relationships between the SWRC parameters, i.e., air-entry suction, water-entry suction, residual suction etc., and as-compacted dry density and water content were obtained using the multiple-linear regression analysis. Such relationships are useful for the prediction of post-compaction suction in the field. The variation of SASW and FFR shear moduli with the suction stress, inferred from SWRCs, was found to be linear. A modified model was proposed, considering the combined effect of void ratio and the suction stress on the shear modulus, represented as Parameter A which was found to decrease as suction increased. The inclusion of suction stress and void ratio within the model variables yields better accuracy of prediction as compared to those models that considered either only suction or water content.
Databáze: OpenAIRE
Externí odkaz: