BY

SHRINANDAN V. KABRA

SY CIVIL

LATTHE EDUCATION SOCIETY’S POLYTECHNIC, SANGLI

GROUND IMPROVEMENT TECHNIQUES

CONTENTS

INTRODUCTION WHY IS IT NECESSARY ?

• TYPES OF TECHNIQUES CONCLUSION ACKNOWLEDGEMENT

‘‘ Ground improvement  is the primary

application of many geotechnical construction

techniques , permitting construction on soils by changing their

characteristics. ’’

WHAT IS GROUND IMPROVEMENT ?

WHY GROUND IMPROVEMENT IS NECESSARY?‘‘ Subsurface conditions can vary greatly

within a single job site and the characteristics of the in

situ soil play a crucial role in determining which ground

improvement technique or group of techniques is best . ’’

TYPES OF IMPROVEMENT TECHNIQUES• Dry soil mixing• Wet soil mixing• Dynamic compaction• Injection system for expansive soils.• Vibro compaction• Vibro piers• Vibro replacement• Preloading• Vacuum Consolidation

DRY SOIL MIXING

• This is the most common method used for ground improvement that improves the characteristics of soft, high moisture content clays, peats, and other weak soils, by mechanically mixing them with dry cementing material binder to create soil concrete.

• The process is often used in high ground water conditions and has the advantage of producing practically no spoil for disposal.

WET SOIL MIXING

• Deep Mixing Method, is a ground improvement technique that improves the characteristics of weak soils by mechanically mixing them with cementing binder slurry.

• Wet soil mixing is best suited for soils with moisture contents up to 60 %

• Wet sampling in fresh columns and coring of cured columns can be used to verify strength. Test columns can be excavated for visual inspection of the soil concrete

DYNAMIC COMPACTION

INJECTION SYSTEMS FOR EXPANSIVE SOILS

VIBRO COMPACTION

• This method is been adopted in DUBAI for the constructions on palm island.

• Vibro compaction rigs can be fully instrumented with an on-board computer to monitor parameters during vibro compaction. Monitoring these parameters allows the operator to correct any deviations in real-time during the construction process to keep the vibro compaction within project specifications.

VIBRO AGGREGATE PIERS

VIBRO REPLACEMENT (STONE COLUMNS)

Preloading has been used for many years without change in the method or application to improve soil properties. Preloading or pre-compression is the process of placing additional vertical stress on a compressible soil to remove pore water over time. The pore water dissipation reduces the total volume causing settlement. Surcharging is an economical method for ground improvement. However, the consolidation of the soils is time dependent, delaying construction projects making it a non-feasible alternative.

PRELOADING

• Vacuum Consolidation is an effective means for improvement of saturated soft soils. The soil site is covered with an airtight membrane and vacuum is created underneath it by using dual venture and vacuum pump. The technology can provide an equivalent pre-loading of about 4.5m high conventional surcharge fill. Vacuum-assisted consolidation preloads the soil by reducing the pore pressure while maintaining a constant total stress.

VACUUM CONSOLIDATION

• https://www.haywardbaker.com

• https://www.myopencourses.com

• https://www.bauer.de

ACKNOWLEDGEMENT

In absence of proper ground surface or when ground is unable to carry large loads, the external agencies has to be involved in order to increase the bearing capacity of soil. To make it up to the mark these methods play a major role in making up the ground surface and improving its characteristics and features. Using these modern techniques not only helps in improving ground but also make it eligible for construction of big structures that include multi storey building, public buildings etc. Thus using these ground improvement techniques is resulting dual advantage of strength full soil and large structure.

CONCLUSION

THANK YOU..!!