CHAPTER ONE
1.1 INTRODUCTION
When a project encounters difficult foundation conditions, possible alternate solutions are:
Avoid the particular site
Design the planned structure accordingly.
Remove and replace unsuitable soils.
Attempt to modify the existing ground.
Relatively few options are available in choosing the ground materials and site conditions that must be accounted for in the design of highway projects. The project must be constructed under the conditions that are present at the particular site; minimal disturbance to existing elements of the roadway is also a key control factor in the selection and design of the rehabilitation or reconstruction scheme (Woodward 2005).
1.2 OBJECTIVES OF GROUND IMPROVEMENT
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. Ground Improvement provides a fast-track vehicle (Raison 2004).
1.3 SCOPE
This paper is an integrated approach to ground improvement solutions in highway engineering, its objectives and the identification of various methods of ground improvement.
CHAPTER TWO
2.1 GROUND IMPRROVEMENT METHODS
Classification of Ground improvement Techniques: There are four groups of Ground Improvement techniques
1. Mechanical Modification:
Soil density is increased by the application of mechanical force, including compaction of surface layers by static vibratory such as compact roller and plate vibrators.
2. Hydraulic Modification:
Free pore water is forced out of soil via drains or wells.
Course grained soils; it is achieved by lowering the ground water level through pumping from boreholes, or trenches.
In fine grained soils the long term application of external loads (preloading) or
References: Jean- Paul Rodrigue, Claude Comtois, Brian Slack (2013). ”The geography of transport system” James Burke (2007) Federal Highway Administration (2004). “Dynamic compaction” John Woodward (2005) A.K.L. Kwong, C.K. Lau, C.F. Lee (2001). “Soft soil engineering” W Michael P. Moseley, Klaus Kirsch (2004). “Ground improvement” Ulrich Smoltczyk (2003) Chris A. Raison (2004). “Ground and soil improvement” Klaus kirsch, Fabian kirsch (2010) Richard Robinson, Bent Thagesen (2004). “Road engineering for development” second edition. Klaus Kirsch, Alan Bell (2012). “Ground improvement” third edition. Ian Smith (2013). “Smiths elements of soil mechanics” Minna Karstunen, Martino Leoni (2008) Hamed Niroumand, Khairul Anuar kassim, Ramli Nazir (2011). “Soil improvement by soil replacement method” M Krishna R. Reddy, Milind V. Khire, Akram N. Alshawabkeh (2008). ”Geosustainability and Geohazard mitigation” Klaus Kirsch, Alan Bell (2012) Manjriker Gunaratne (2004). “The foundation engineering”