Heavy mineral contents and provenance of Late Quaternary sediments of southern Kerala, Southwest India

749-757Present paper deals with provenance and depositional history of the Late Quaternary sediments including heavy mineral placers in the coastal lands of Kollam district, SW India.  Kollam coast is endowed with estuaries, old coastal plains with ridge-runnel systems and  barrier beaches. Mineralogical analysis reveals that sediments in the estuarine basins that are seen entrenched over the Neogene sedimentary deposits were derived from dual sources.  Heavy mineral residues of the upper estuarine zones are generally garnet bearing and are of alluvial origin.  At the same time, sediments in the lower estuary are garnet-free and are derived from the nearby littoral zones during the tidal processes.  Heavy mineralogical data together with statistical analysis discloses that the garnet and pyribole-free heavy mineral suite in the beaches and nearby coastal plains of the Kollam coast are primarily derived from denudation of the Neogene sedimentary deposits in the coastal lands.  They are evolved during the rising phases of the sea level in the Late Quaternary period

Laterite as a base and subbase material for flexible pavement – a review

Rapid economic growth is leading to ubiquitous expansion in highway projects around the world. Utilization of natural aggregate resources for the construction of flexible pavement has led to uncontrollable quarrying in the state of Kerala. The recent landslides in Kerala which took the lives of many people is the aftermath of extensive quarrying activities. Utilization of treated native soil in the structural layers (Subbase and base) of flexible pavement can widely avert the danger associated with ecological imbalance due to quarrying. The main objective of this review article is to enlighten the researchers and practicing engineers about the key advances developed in the last 10 years for utilizing native laterite soil in the base and subbase layers of flexible pavement. On the basis of various researches, laterite soil treated with lime, cement and other additives showed considerable enhancement in the compaction characteristics, unconfined compressive strength (UCS) and California Bearing Ratio (CBR). As stipulated by MORTH (Ministry of Road Transport and Highways), for a layer to be suitable as a subbase material in flexible pavement, minimum CBR value must be 30%. From the extensive review, it was found that the treated laterite soil satisfied the MORTH criteria for use as a subbase layer in flexible pavement.&#x0D; Keywords- Ferrocement, cyclic loading, flexural behavior, precast ferrocement wall, dynamic analysis, static analysis</jats:p