No abstract

Soil stabilization, using a variety of stabilizers, is a common method used by engineers and designers to enhance the properties of soil. The use of nanomaterials for soil stabilization is one of the most active research areas that also encompass a number of disciplines, including civil engineering and construction materials. Soils improved by nanomaterials could provide a novel, smart, and eco-and environment-friendly construction material for sustainability. In this case, carbon nanomaterials (CNMs) have become candidates for numerous applications in civil engineering. The main objective of this paper is to explore improvements in the physical properties of UKM residual soil using small amounts (0.05, 0.075, 0.1, and 0.2%) of nanocarbons, that is, carbon nanotube (multiwall carbon nanotube (MWCNTs)) and carbon nanofibers (CNFs). The parameters investigated in this study include Atterberg's limits, optimum water content, maximum dry density, specific gravity, pH, and hydraulic conductivity. Nanocarbons increased the pH values from 3.93 to 4.16. Furthermore, the hydraulic conductivity values of the stabilized fine-grained soil samples containing MWCNTs decreased from 2.16 − 09 m/s to 9.46 − 10 m/s and, in the reinforcement sample by CNFs, the hydraulic conductivity value decreased to 7.44 − 10 m/s. Small amount of nanocarbons (MWCNTs and CNFs) decreased the optimum moisture content, increased maximum dry density, reduced the plasticity index, and also had a significant effect on its hydraulic conductivity.

No abstract

Bridges are one of the most critical parts of transportation networks that may suffer damages against earthquakes. Also, seismic responses of most bridges are significantly influenced by soil-structure interaction effects. Taking out expansion joints in the bridges may cause many difficulties in design and analysis due to the complexity of soil-structure interaction and nonlinear behavior. The secondary loads on an IAB include seismic load, temperature variation, creep, shrinkage, backfill pressure on back wall and abutment, all of which cause superstructure length and stress variations in girder changes. The purpose of this study is to recognize the most effective parameters of analysis IABs. Findings show that the backfill material behind the IABs has a significant effect on the performance of IABs. Using a compressible material behind the abutments would enhance the in-service performance of IABs. Finally, behaviour of abutment may be greatly affected by thermal load and soil pressure. Thermal expansion coefficient significantly influences girder axial force, girder bending moment, and pile head/abutment displacement.

No abstract

There are several questions that are not well understood with respect to the long-term stability characteristics of lime-treated clay soils in spite of being used as a conventional technique to improve the properties of clay soils. This paper investigates the influence of freeze-thaw cycles on the unconfined compressive strength of kaolinite and illite mixed with silica sand. The results of this study show that an increase in the number of freeze-thaw cycles decreases the unconfined compressive strength. The role of lime increasing the soil strength is more significant in the case of samples exposed to freeze-thaw cycles compared to those not exposed to freeze-thaw cycles. The effect of freeze-thaw cycles on the dry unit weight and moisture content is insignificant compared to unexposed samples. The maximum volumetric changes occurred in the first freeze-thaw cycle, and afterward, the rate of volume change decreased with an increase in freeze—thaw cycles.

No abstract

The quality of the subgrade is depending on the geotechnical properties, strength and the stabilization technique adopted for problematic soil in order to increase the bearing value. In Malaysia, soft soil is a challenging due to very low strength value and low California Bearing Ratio (CBR) value as well. The soil stabilization process is conducted to increase bearing capacity of marine soil. An experimental works cover from identification of basic soil properties by index test, compaction test and CBR test. Though, the marine soils have to be treated and stabilized with available methods like using natural materials or additive agents. In this study, geotechnical characteristics of marine soil stabilized with CSP content were determined. The unsoaked treated marine soil stabilized with CSP was investigated. Four different compounds of the soil with 2.5, 5, 7.5 and 10% of CSP were mixed and added to determine the unsoaked CBR of the stabilized soil compounds. The results show the inclusion of CSP reduced the plasticity of the soil and highest dry density was decreased with an increase in the optimum water content. Moreover, by increasing the content of CSP the highest CBR value at 2.5 and 5.0 mm penetrations were achieved. The increasing percentage volume of water usage indicates the decreasing value of CBR. The results indicated that CSP contents have potential as a natural stabilizer for applications such as road sub-base material in road construction. The road sub-base will gain great strength with addition of CSP on marine soil