Soil stabilization

About: Soil stabilization is a research topic. Over the lifetime, 3161 publications have been published within this topic receiving 48437 citations.

A geoenvironmental application of burned wastewater sludge ash in soil stabilization

Abstract: This paper studied the use of burned sludge ash as a soil stabilizing agent. The sludge ash was obtained from a public wastewater treatment plant, and it was burned at 550 °C. Different percentages of burned sludge ash were mixed with three different types of clayey soil. A laboratory study consisting of Atterberg’s limits test, unconfined compressive strength test, standard proctor density test, and swelling pressure test were carried out on samples treated with burned sludge at different percentages by dry weight of the clayey soils. The results show that the addition of 7.5 % of the burned sludge ash by the dry weight of the soil will increase the unconfined compressive strength and maximum dry density and also decrease the swelling pressure and the swell potential of the soil. The addition of percentage higher than 7.5 % by dry weight of the soil decreases both the maximum dry density and the unconfined compressive strength; as a result it showed less effectiveness in stabilizing the soil. The conclusion of this research revealed that the burned sludge ash can be used as a promising material for soil stabilization.

An Innovative Laboratory Box for Testing Nail Pull-Out Resistance in Soil

Abstract: This paper introduces a new soil nail pull-out box with full instrumentation for investigating the soil nail pull-out shear resistance under different controlled conditions. The new box has overcome some limitations of previous pull-out boxes developed by other researchers, the first author, and his co-workers. The box has the following new features: (a) comprehensive transducers are installed, (b) an extension chamber is provided to house an extension part of the soil nail to keep the nail length inside the box constant throughout the testing, (c) a waterproof front cap is placed to cover and seal the soil nail head so that back water pressure can be applied to accelerate the saturation of the soil, and (d) a pressure grouting apparatus is constructed to make it possible to investigate the influence of the cement grouting pressure. The pull-out box can be used to study influences of (a) hole drilling process and stress release, (b) degree of saturation of the soil, (c) cement pressure grouting, (d) overburden pressure, etc. Two copies of such a new soil nail pull-out box have been constructed to accelerate the testing program. A series of soil nail pull-out tests has been conducted using the two boxes. This paper presents details of the new pull-out box, from design, boundary effect analysis, and instrumentation to setup. Typical results from soil nail pull-out tests are presented and discussed.

Stability Problems of Collapsing Soil

Abstract: Where collapsing soils exist in extensive areas of canal construction, stabilizing the foundation subsoils by ponding method is necessary before embankments and linings are built. As these soils a may still be somewhat critical after collapse, slope stability analyses must include this hazard In interpretation of soil strengths and safety factors. A procedure is presented for delineating collapsible soils and includes settlement records from 16 miles of preconstruction ponding treatment on the San Luis Canal, California, substantiating the criteria. Soil strength values from laboratory tests, which considered the critical nature of such soils, were used in a stability study. Safety factors were adjusted to account for earthquake stresses, and consideration was given to reduced ultimate strength and limits of strain to resist bulging and cracking of the lining. Improved stability was attained by zoning the canal embankments and compacting foundation surfaces with extra heavy pneumatic rollers.

Structural Characteristics of Laterite Soil Treated by SH-85 and TX-85 (Non-Traditional) Stabilizers

Abstract: Soil stabilization is the process of improving the physical and engineering properties of a soil to obtain some predetermined targets. Nowadays, among the different methods of soil improvement, using chemical additives for soil stabilization in order to increase soil strength parameters and loading capacity getting more attention. The chemical stabilization technology is a chemically modified method that can stabilize or reinforce those soils with weak engineering properties. Various types of chemical additives (in liquid and powder form) are actively marketed by a number of companies. The stabilizing mechanisms of these products are not fully understood, and their proprietary chemical composition makes it very difficult to evaluate the stabilizing mechanisms and predict their performance. This research was carried out in an attempt to identify the time-dependent reactions between laterite soil and two type of nontraditional additives (TX-85, SH-85) by macroand micro structure study. The employed tests were unconfined compression strength (UCS), Atterberg limits, pH, and scanning electron microscopy (SEM). Based on the results it was found that the both of additives can increase the laterite soil strength, as the increment for SH-85 and TX85 is around 5 and 4 times more than untreated soil respectively, which is gained in first 7 days of curing. Also the results of SEM showed that the porosity of untreated soil filled by the new component, so the treatment with SH-85 and TX-85 contributed to denser soil fabric.

Soil water retention and vegetation survivability improvement using microbial biopolymers in drylands

Abstract: Vegetation cover plays a vital role in stabilizing the soil structure, thereby contributing to surface erosion control. Surface vegetation acts as a shelterbelt that controls the flow velocity and reduces the kinetic energy of the water near the soil surface, whereas vegetation roots reinforce the soil via the formation of root-particle interactions that reduce particle detachment. In this study, two vegetation-testing trials were conducted. The first trial was held on cool-season turfgrasses seeded in a biopolymer-treated site soil in an open greenhouse. At the end of the test, the most suitable grass type was suggested for the second vegetation test, which was conducted in an environmental control chamber. In the second test, biopolymers, namely, starch and xanthan gum hydrogels (pure starch, pure xanthan gum, and xanthan gum-starch mixtures), were tested as soil conditioners for improving the water-holding capacity and vegetation growth in sandy soils. The results support the possibility that biopolymer treatments may enhance the survival rate of vegetation under severe drought environments, which could be applicable for soil stabilization in arid and semiarid regions.