This document discusses various soil improvement techniques including mechanical, chemical and in-situ stabilization methods. It describes processes like
Identify the type of techniques required for various soils LEARNING MATERIAL 1.1 Need for Ground Improvement: Generally Engineers design Foundation and other structures basing on soil investigation. If soil good at lesser depth shallow foundation can be laid, if hard stratum available at higher depth, Deep foundation can be laid. In some cases, Deep foundation becomes uneconomical, it becomes a problem practically. So there need arises to improve the ground conditions by ground improvement. [...] is not damaged by settlement, - Or choose a very flexible construction which accommodates differential movement or allows for compensation. 3. Remove and replace unsuitable soils: Remove organic topsoil, which is soft, compressible, and volumetrically unstable. This is a standard precaution in road or foundation construction. 4. Attempt to modify the existing ground 1.2 Objective of Ground Improvement Techniques The most common traditional objectives include improvement of the soil and ground [...] sites and borrow areas are difficult to find and the soil improvement alternatives becomes the best option, technically and economically. Where a project encounters difficult foundation conditions, possible alternative solutions are: 1. Avoid the particular site: Relocate a planned highway or development site. 2. Design the planned structure accordingly: Some of the many possible approaches are to: - Use a raft foundation supported by piles, - Design a very stiff structure which is not damaged
In deep foundation construction, the stability and performance of the foundation system are paramount. Ground improvement plays a vital role in ensuring that the soil can adequately support the loads imposed by structures. By enhancing the mechanical properties of the ground—these techniques help mitigate risks associated with settlement, bearing capacity failures, and soil liquefaction. This is particularly important in challenging soil conditions where traditional foundation solutions may be [...] Ground improvement techniques encompass a variety of methods designed to enhance the engineering properties of soil and rock to meet specific project requirements. These techniques are employed to increase soil strength, reduce compressibility, and improve overall stability—making them crucial for the successful execution of construction projects. Common ground improvement methods include aggregate piers, rigid inclusions, stone columns, soil mixing, compaction grouting, permeation grouting, [...] Jet grouting is a ground improvement technique that uses high-pressure jets to inject grout into the soil, creating soil-cement columns that enhance strength and stability. This method is effective for a wide range of soil types—including sands, silts, and clays. It is used for foundation support, excavation stabilization, and creating impermeable barriers for groundwater control. The benefits include increased soil strength, reduced permeability, and versatility in application for various soil
structure that does not require excessive maintenance. Such soils can be stabilized to form a construction pad or a long-term subsurface layer capable of carrying pavement applied loads. In all cases, the provision for a uniform soil relative to textural classification, moisture, and density in the upper portion of the subgrade cannot be over emphasized. This uniformity can be achieved through soil sub-cutting or other techniques. Five techniques can be used to improve the strength and reduce [...] technique is rarely used to improve the foundations of higher-volume roadways. It is more commonly used as a foundation or subbase layer for low-volume roadways, where the import of higher-quality embankment materials is restricted from a cost standpoint. The concept of soil encapsulation is to keep the fine-grained soils at or slightly below optimum moisture content, where the strength of these soils can support heavier trucks and traffic. See Section 6D-1 - Embankment Construction, for [...] 6H-1 Design Manual Chapter 6 - Geotechnical 6H - Foundation Improvement and Stabilization Foundation Improvement and Stabilization 1 Revised: 2013 Edition A. General Information Soft subgrade and moisture-sensitive soils such as expansive soils, frost-prone soils, and collapsing soils present a construction challenge as well as a pavement performance challenge. Proper treatment of problem soils and the preparation of the foundation are important to ensure a long-lasting pavement structure that
CHAPTER 21 SOIL IMPROVEMENT 21.1 INTRODUCTION General practice is to use shallow foundations for the foundations of buildings and other such structures, if the soil close to the ground surface possesses sufficient bearing capacity. However, where the top soil is either loose or soft, the load from the superstructure has to be transferred to deeper firm strata. In such cases, pile or pier foundations are the obvious choice. [...] There is also a third method which may in some cases prove more economical than deep foundations or where the alternate method may become inevitable due to certain site and other environmental conditions. This third method comes under the heading foundation soil improvement. In the case of earth dams, there is no other alternative than compacting the remolded soil in layers to the required density and moisture content. The soil for the dam will be excavated at the adjoining areas and [...] adjoining areas and transported to the site. There are many methods by which the soil at the site can be improved. Soil improvement is frequently termed soil stabilization, which in its broadest sense is alteration of any property of a soil to improve its engineering performance. Soil improvement 1. Increases shear strength 2. Reduces permeability, and 3. Reduces compressibility The methods of soil improvement considered in this chapter are 1. Mechanical compaction 2. Dynamic compaction 3.
of the organics and the soil and aggregate pier behavior. More commonly, rigid inclusions or confined aggregate piers with polymeric sleeves are being utilized for organic soil sites to reduce the risks of poor long-term performance in these soil types. This paper presented three case histories where three different types of ground improvement systems were utilized to provide control of foundation settlement using confined and grouted / cemented aggregate elements that resulted in significant [...] at 3,000 kN (150% of design load). The granular footing pad is an important design component, resulting in about one-half of the total top-of-footing settlement measured. CONCLUSIONS Ground improvement for foundation support in organic soils has been implemented for decades. Uncemented or unconfined aggregate piers can be used, when appropriate, and with careful attention to the thickness and compressibility of the organic soil layer, and the consequences of long-term behavior of the organics [...] typically consist of aggregate columns with cementitious binder, or batched quantities of sand-cement, and concrete. Confined aggregate piers typically consist of compacted aggregate within a pre-installed extensible shell. The primary purpose of these types of ground improvement elements is to either prevent bulging of the aggregate or to completely bypass the compressible layer and transfer foundation loads to a less compressible soil layer. This paper presents three case histories where
This paper gives an overview of techniques that are commonly used to improve the performance of saturated clayey soil in situ, its functions, methods of
Soil improvement and soil stabilisation can be used for fills, foundations, subgrade improvement, slope repairs, working platforms and hardstandings. Soil improvement Soil improvement is generally achieved by adding binders. It is sometimes termed soil modification in the literature. [...] The benefits Soil improvement and soil stabilisation are proven civil engineering techniques. Treating materials in-situ is efficient, cost effective and offers a number of benefits. [...] Ground Investigation and its procurement Ground investigation for foundations and ground contamination can be insufficient for soil improvement and stabilisation. There are two important constraints that are specific to soil improvement and stabilisation: • Organic compounds that impair the chemical reactions of lime and cement, • Sulfates in the soil that cause an expansive chemical reaction with lime.