The specific techniques that can be utilised for ground improvement are:
- preloading or surcharging with sand, either with or without vertical drains;
- various compaction techniques including vibratory methods,
- soil removal and replacement, stone columns, and geotextile encased sand columns; and
- in-situ admixtures like lime, cement and fly ash.
What is ground improvement and why is it important?
Ground improvement, or ground modification, is defined as the alteration of site foundation soils or project earth structures to provide better performance under design and/or operational loading conditions (Schaefer et al., 2012 ). Ground improvement is necessary when poor soil conditions are encountered for the purpose at hand.
What are the conventional methods of ground improvement?
The conventional techniques used to deal with such challenges are compaction, chemical grouting, use of cement, lime or fibers, installation of nails, piles or sheets, etc. Though all these ground improvement methods are associated with limitations and disadvantages.
What is meant by ground improvement by grouting?
Ground Improvement by Grouting. Grouting can be defined as controlled injection of material, usually in a fluid phase, into soil or rock in order to improve the physical characteristics of the ground. Major ground treatment methods include; Grouting processes.
What is the best way to improve the ground?
Ground Improvement by Structural Fill. Basis of this philosophy is to replace a weak soil with a better one. Use lightweight materials instead of heavier earth fills above weak ground is a recent advancement of this method. Major ground treatment methods include; Removal and replacement.
What is ground improvement method?
Ground improvement, or ground modification, is defined as the alteration of site foundation soils or project earth structures to provide better performance under design and/or operational loading conditions (Schaefer et al., 2012). From: Encyclopedia of Geology (Second Edition), 2021.
What are the objectives of ground improvement techniques?
Ground improvement is carried out for various objectives: to improve bearing capacity and reduce settlement of soft ground, prevent earthquake liquefaction, control groundwater, stabilize excavation bottom, prevent deformation of surrounding ground, or clean up contaminated ground.
What are the factors to be considered to select a ground improvement technique?
The selection of soil improvement method is governed by several factors like soil type, equipment availability, cost, construction period, skills, and past experiences. Soil type is one of the critical factors that can influence the selection of one soil improvement method over another.
What are the benefits of ground improvement?
Benefits of ground improvement include:A quicker project time as design and implementation are fast.Reduced or no disposal costs as hardly any waste.Easier sub-structure design and construction.Effective on various soil types.Equipment designed to meet demanding needs of different sites.
What are the various methods of ground improvement techniques?
Typical ground improvement techniques are listed below:Dynamic Compaction.Jet Grouting.Deep Soil Mixing.Ground Freezing.Lime Stabilization.Prefabricated Vertical Drains (PVDs)
What are the major categories of ground improvement?
They listed seven main categories including densification, consolidation, load reduction, reinforcement, chemical treatment, thermal stabilization, and biotechnical stabilization. ...
What is the best soil improver?
Compost can be made from garden waste, grass cuttings, shredded newspaper and kitchen waste. Leaf mould also makes an excellent soil improver and makes good use of leaves cleared from the lawn, however nutrient levels are quite low.
Which techniques are used to reduce the soil settlement?
reduce the expected settlement of soft soil. three techniques are soil removal and replacement, preloading technique, and finally the vertical drains.
Why are soil improvement techniques used in geotechnical engineering?
Various geotechnical techniques are used to re-engineer the existing soil to improve its characteristics as well. Soil improvement is usually done to meet the requirements of the type of structure that is to be constructed on that particular piece of land.
What is ground improvement in geotechnical engineering?
This technique involves compressing the soil by releasing large steel rigs from a specific height, usually between forty and eighty feet. This method efficiently compresses loose soils in the areas of concern. After compacting is complete, the ground area is then dug out to process and replace engineered fill.
Which term is need for ground improvement?
Jet grouting is a general term used by grouting contractors to describe various construction techniques used for ground modification or ground improvement.
What is the role of ground improvement in foundation engineering?
Compaction techniques are increasingly used to solve a wide range of foundation problems and their scope now extends beyond the treatment of granular materials to include many silty or clayey soils.
What is the role of ground improvement in foundation engineering?
Compaction techniques are increasingly used to solve a wide range of foundation problems and their scope now extends beyond the treatment of granular materials to include many silty or clayey soils.
What is the need for improving the ground explain in brief the best method suitable for various soils?
The ground can be improved by adapting certain ground improvement techniques. Vibro-compaction increases the density of the soil by using powerful depth vibrators. Vacuum consolidation is used for improving soft soils by using a vacuum pump....Grouting TechniquesPermeation.Compaction Grouting.Claquage.Jet Grouting.
What is ground improvement PPT?
Ground Improvement refers to a technique that improves the engineering properties of the soil mass treated. Usually, the properties that are modified are shear strength, stiffness and permeability. Ground improvement has developed into a sophisticated tool to support foundations for a wide variety of structures.
How do you strengthen the ground?
TECHNIQUES USED FOR IMPROVING BEARING CAPACITY OF SOILIncreasing depth of foundation.Draining the soil.Compacting the soil.Confining the soil.Replacing the poor soil.Using grouting material.Stabilizing the soil with chemicals.
How does soil compaction work?
Soil compaction by adding load to induce settlements in advance of the proposed construction. Larger pre-loads will reduce time required for the settlement to occur. The shear strength, stiffness, bearing capacity and stability of the soil.
What is a conventional compaction plant?
Conventional compaction plant are used commonly under highway specification (plant rollers and hand held plant), and involves applying a static stress onto the soil. The applied stress increases the soil density, decreasing air volume, and inhibits root penetration and movement of air and water in the soil.
What is ground improvement?
Ground Improvement or Ground treatment is defined as “controlled alteration of the state, nature or mass behavior of ground materials to achieve an intended satisfactory response to existing or projected environmental and engineering actions”
What is vegetation as ground improvement?
Combining engineering and horticulture, vegetation as ground improvement is the biological reinforcement of soil by plant roots to retain earth masses and prevent soil loss.
How does vibration improve soil?
Ground Improvement by Vibration. Vibration can be used to compact soils and fills. Similar to Vibrating rollers used to compact relatively thin layers of earth fill and bituminous road materials. It involves using vibration to densify the ground in place and to depth either by penetrating the ground with a vibrator or inducing very high level ...
How does thermal stabilization improve ground?
Ground Improvement by Thermal Stabilization. The removal of heat from the soil turning its pore water into ice is a very powerful technique rendering the ground impermeable and, for unconsolidated materials, making them stronger.
What happens when you put loads on the ground?
Applying load on the ground causes it to compress. The extent and time required depends on the arrangement of the ground particles, on the degree of saturation, and on how freely the soil can drain. For loose and particularly unsaturated fills, adding load induces rapid settlement.
What is grouting in soil?
Grouting can be defined as controlled injection of material, usually in a fluid phase, into soil or rock in order to improve the physical characteristics of the ground. Major ground treatment methods include; Grouting processes. Permeation grouting.
What is ground modification?
Ground improvement, or ground modification, is defined as the alteration of site foundation soils or project earth structures to provide better performance under design and/or operational loading conditions (Schaefer et al., 2012 ). Ground improvement is necessary when poor soil conditions are encountered for the purpose at hand. While the poor soil conditions could readily be dealt with by excavating and replacing the soil, or perhaps by using deep foundations, it is often more cost effective to simply improve the soil in place through some type of treatment. As noted by Schaefer et al. (2012), ground modification typically serves one or more of the following primary functions:
What is ground reinforcement?
In situ ground reinforcement is a technique to stabilize existing unstable ground due to the change of geotechnical conditions by nature and/or human activities. Ground anchors, soil nails, micropiles, and slope stabilizing piles have been used as in situ ground reinforcement techniques to mitigate the preceding problems as shown in Fig. 2.13. Also, steel or plastic geogrids are used to reinforce earth. The effectiveness of the reinforcement is governed by its tensile strength and the bond it develops with the surrounding soil. The presence of reinforcement noticeably improves the mechanical properties of granular soil and, depending on confining pressure, various modes of failure can be observed.
What is geotechnical planning?
Geotechnical planning, design, construction and rehabilitation in the early phases of an infrastructure project can significantly contribute to the overall sustainability of that particular development by making appropriate choices related to several aspects of the project. These choices include strategies, materials and technologies that can be summarised as follows:
What is soil compaction?
Soil compaction by various means has been practis ed for ground improvement in road building dating back to Roman times and even earlier. Particularly in the early 18th century, the strategic importance of inter-urban travel was recognised, and the need arose for high standard roads leading to the establishment of the Engineering Corps and the School for Bridges and Roads in France during that period. In 1765, a graduate from that school, Pierre-Marie Tresaguet, followed Roman work and continued the development of road pavement structures with sub-base layers [26]. At the same time, Thomas Telford from Scotland and John Metcalf from England applied similar design philosophies in Britain. A major issue with their design was the use of large stones in the foundation of the pavement, which made pavement building slow and expensive. Later, John McAdam from Scotland made a significant innovation by suggesting a dense layer of smaller-sized rocks instead of large stones [26]. Due to particle interlocking, these layers of small rocks provide equivalent support to a large-sized stone foundation. Even then, manual labour was the primary mode of construction and neither the underlying soil nor the pavement layers received significant mechanised compaction. This led to the development of compaction equipment in road pavement construction.
What are the additives used in soil?
The most common artificial additives are (in order of usage) portland cement (and cement-fly ash), lime (and lime-fly ash), and bitumen and tar. The reason of their popularity is that they are applicable to a considerable range of soil types, they are widely available, their costs are relatively low, and they are environmentally acceptable. The purpose of mixing additives is to increase strength and durability; reduce permeability, deformability, and erodibility; provide volume stability and control variability. In Fig. 2.11, examples of physical ground stabilization are shown.
What is habitat enhancement?
Habitat enhancement aims to expand areas of good habitat for sea urchins, and to promote colonization of algae on those reefs as food for the sea urchins ( Morikawa, 1999 ). In Japan, stones and concrete blocks have been introduced to increase the area of appropriate habitat ( Mottet, 1976). Since the Coastal Fishing Ground Improvement and Development Law was established, habitat enhancement projects termed “Large-scale Construction of Nursery,” “Nearshore Nursery Construction,” or “Wide Area Nursery Construction” have been implemented in the period since 1976.
What is ground improvement?
Ground improvementis the procedure typically defined as using mechanical means to improve poor ground conditions. Ground improvement methods improve the engineering properties of the soil mass which is treated to meet project performance requirements. Objectives.
What is the purpose of deep mixing?
The Deep Mixing Method (DMM) is an in-situ modification technique which is performed to improve strength, reduce liquefaction potential, lower permeability, reduce deformations and allow constructio...
Who created the Geotechnical Engineering Photo Album?
Geotechnical Engineering Photo Album: A collection of photographs for educational instruction by Ross W. Boulanger and J. Michael Duncan
Ground Improvement by Vibration
Ground Improvement by Adding Load Or Increasing Effective Stress
Ground Improvement by Structural Reinforcement
Ground Improvement by Structural Fill
Ground Improvement by Admixtures
Ground Improvement by Grouting
- Grouting can be defined as controlled injection of material, usually in a fluid phase, into soil or rock in order to improve the physical characteristics of the ground. Major ground treatment methods include; 1. Grouting processes 2. Permeation grouting 3. Hydrofracture grouting 4. Jet grouting 5. Compaction, squeeze and compensation grouting 6. Ca...
Ground Improvement by Thermal Stabilization
Ground Improvement by Vegetation