This paper presents the results of a laboratory study undertaken to investigate the effect of Marble dusts on strength and durability of an expansive soil stabilized with optimum percentage of Rice Husk ash (RHA). The optimum percentage of RHA was found out be 10% based on Unconfined Compressive Strength (UCS) tests. Marble dust was added to RHA stabilized expansive soil up to 30%, by dry weight of the soil, at an increment of 5%. Compaction tests, UCS tests, Soaked California Bearing Ratio (CBR) tests, Swelling pressure tests and Durability tests were conducted on these samples after 7 days of curing. The UCS, and Soaked CBR of RHA-stabilized expansive soil increased up to 20% addition of Marble dust. Further addition of Marble dust had negative effects on these properties. The Maximum Dry Density(MDD) and Swelling pressure of expansive soil goes on decreasing and Optimum Moisture Content (OMC) goes on increasing irrespective of the percentage of addition of Marble dust to RHA stabilized expansive soil. From the Durability test results it was found that the addition of Marble dust had made the RHA stabilized expansive soil durable. For best stabilization effect the optimum proportion of Soil: Rice husk ash: Marble dust was found to be 70: 10: 20.

Effect of marble dust on strength and durability of Rice husk ash stabilised expansive soil

A soil-shrinkage curve (SSC) can be defined as the characteristic volume–water content relation under free external stress conditions. A SSC is traditionally divided into three characterist...

Correlation between Soil-Shrinkage Curve and Water-Retention Characteristics

In the Ganges-Brahmaputra (G-B) delta, periodic flooding of the land surface during the tidal cycle coupled with enormous sediment delivery during the monsoon promotes sediment accretion and surface elevation gain through time. However, over the past several decades, widespread embankment (“polder”) construction in the G-B tidal delta plain has led to numerous environmental disturbances, including channel siltation and tide range amplification. While previous research indicates that rates of sediment accretion are relatively high in the G-B tidal delta plain, it remains unclear if and how surface elevation is maintaining pace with relative sea-level rise (RSLR) in this region. In this study, we utilize an array of surface elevation tables, sediment traps, and groundwater piezometers to provide longitudinal trends of sedimentation and elevation dynamics with respect to local platform elevation and associated hydroperiod. Two hydro-geomorphic settings of the Sundarbans mangrove forest are compared: higher elevation stream-bank and lower elevation interior. Seasonal measurements over a time span of 5 years reveal that elevation gain is occurring in all settings, with the highest rates observed at elevated stream-bank zones. Elevation gain occurs primarily in response to sediment accretion, with possible minor contributions from pore-water storage and swelling of clay minerals during the monsoon season (i.e., belowground biomass and organic contribution is minimal). As a result, elevation loss and shallow subsidence in the G-B delta is unlikely to be caused by compaction of organic-rich soils, but rather appears to be controlled by seasonal lowering of the groundwater table and compaction of clay minerals. Rates of surface elevation gain in the Sundarbans greatly exceed rates of RSLR and more closely follow rates of RSLR augmented from tide range amplification, indicating that this landscape is adapting to human-induced environmental change. The proceedings of this study underscore the adaptability of the natural G-B tidal delta plain to local environmental disturbances, with the caveat that these defenses may be lost to future upstream reductions in sediment supply.

https://digitalcommons.odu.edu/cgi/viewcontent.cgi?article=1393&context=oeas_fac_pubs

Surface elevation and sedimentation dynamics in the Ganges-Brahmaputra tidal delta plain, Bangladesh: Evidence for mangrove adaptation to human-induced tidal amplification

Swelling soils are a major geological hazard worldwide and their identification is a major concern. Swelling is due to the presence of clay minerals with a potential to accommodate water within their crystal structure. Three common groups, namely smectite, illite and kaolinite, have been identified as indicators of high, moderate and low swelling potential soils where in abundance. This study assessed the potential of spectral data as a tool to recognize the presence of these minerals in soils of varying swelling potential collected from the Antequera area of southern Spain, with the aim of establishing spectral parameters that would in future be applied in remote sensing applications for mapping swelling soils. The coefficient of linear extensibility (COLE) and the linear extensibility (LErod), which are established methods for assessing swelling potential and tentative clay mineral allocation, were used as the controlling methods to classify the soils into swelling potential groups and to assign them to...

Effectiveness of spectroscopy in identification of swelling indicator clay minerals

https://ro.ecu.edu.au/cgi/viewcontent.cgi?article=9615&context=ecuworkspost2013

K.V. Ramana

Papers

Expansive Soils: Problems and Practice in Foundation and Pavement Engineering