An earthwork design requires to consider the influence of severe climatic conditions on enduring performance of soils treated with chemical additives. This study was focused on investigating the mechanical behavior of a lime and cement-treated cohesive soil under the effects of repeated cycles of wetting and drying. The soil samples were prepared by adding different concentrations of cement (2, 6, 10, 12, 16, 20%) and quicklime (2, 4, 6, 8, 10%). Due to low-plastic nature of the host soil, the effectiveness of cement to reduce the plasticity of soil was relatively higher compared to lime-treatment. Likewise, an increase in optimum moisture and decrease in maximum dry unit weight was observed for both the additives and these effects were significant for lime treated soil compared to cement. Moreover, an increase in strength from 0.57 MPa to 12.9 MPa at 20% cement and from 0.57 MPa to 2.03 MPa at 2% lime was observed in unconfined compressive strengths (UCS) tests on soil samples. To investigate the durability characteristics of the treated soil, the samples were subjected to 12 cycles of wetting and drying with each cycle consisting of 5 hours of immersion in potable water and subsequent drying in oven for 43 hours. The compressive strength, volume change and weight loss of soil samples were determined at the 1st, 3rd, 6th, 9th and 12th cycle. It is observed that the durability behaviour of treated soil is multipart due to parallel processes of positive aging (hydration process associated with binding agents) and negative aging (induced weathering). For a sustainable mechanical performance of the treated soil, an optimum dose of 6% lime or 16% cement is recommended and some correlations are proposed to quantify the effects of repeated wetting and drying.

In recent years, Fiber Reinforced Polymers (FRP) have emerged as useful materials for structural strengthening and rehabilitation. The main aspire of this research is towards evaluating the efficiency of Carbon Fiber Reinforced Polymers (CFRP) in enhancing the shear strength of deep beams. The research work included construction and testing of eight (08) reinforced concrete deep beams. Two of the beams, designated as control beams, were without any shear reinforcement. Remaining six beams were divided into three groups, with each group having two identical beams. Beams in one of these groups were strengthened with conventional type of steel web reinforcement. Remaining two groups were strengthened externally by CFRP sheets with different orientations of CFRP. Magnitude of load causing shear cracks to initiate, and the failure load of each beam was recorded. Significant increase in overall load carrying capacities was observed with both CFRP sheets and web steel reinforcement. CFRP was found to be considerably effective in delaying the initial appearance of shear cracks, thereby improving the serviceability limit state of beams. Beams with CFRP orientation perpendicular to the shear cracks showed higher increment in shear strength. In conclusion, CFRP laminates could effectively be used to strengthen existing RC structures deficient in shear strength, and also to reduce/replace internal steel web reinforcement in new RC structures. Material cost comparison of CFRP reinforced beams with conventional web reinforcement is presented, and the general cost effectiveness of structural rehabilitation by means of CFRP is also discussed.

The unchecked and unnoticed disposal of industrial leachates is a common malpractice in developing countries. Untreated effluents from industries drastically deteriorate the soil, altering nearly all of its characteristics. An increase in urbanization has led to construction on these deteriorated lands. In this study, the chemical impact of two industrial effluents, dyeing (acidic) and tannery (basic), is studied on two cohesive soils, i.e., high plastic clay (CH) and low plastic clay (CL). Properties such as liquid limit, plasticity index, specific gravity, maximum dry density, unconfined compressive strength, swell potential, swell pressure, and compression indices decrease with effluent contamination, with the exception of the basic effluent, for which the trend changes after a certain percentage. This study also examines the time variation of properties at different effluent percentages, finding that unconfined compressive strength of both soils increases with time upon dyeing (acidic) contamination and decreases with tannery (basic). The stabilizing effect of two industrial by-products, i.e., marble dust and ground granulated blast furnace slag (GGBFS) have been evaluated. Unlike their proven positive effect on uncontaminated soils, these industrial by-products did not show any significant stabilization effect on leachate-contaminated cohesive soils, thereby emphasizing the need to utilize special remediation measures for effluent treated soils.

Rainfall-induced landslides are one of the most widespread slope instability phenomena posing a serious risk to public safety worldwide so that their temporal prediction is of great interest to establish effective warning systems. The objective of this study is to determine the effectiveness of elastic wave velocities in the surface layer of the slope in monitoring, prediction and early warning of landslide. The small-scale fixed and varied, and large-scale slope model tests were conducted. Analysis of the results has established that the elastic wave velocity continuously decreases in response of moisture content and deformation and there was a distinct surge in the decrease rate of wave velocity when failure was initiated. Based on the preliminary results of this analysis, the method using the change in elastic wave velocity proves superior for landslide early warning and suggests that a warning be issued at switch of wave velocity decrease rate.