Geotechnical Engineering

Achievements and Future PlanThe division undertakes Sponsored research and Consultancy assignments in the area related to geotechnical investigations for highways; land slide investigations & hazard mitigation; ground improvement for soft and compressible soils; and characterization and utilization of various kinds of waste and marginal materials in road construction. The division has successfully completed a large number of difficult and challenging projects being sponsored by agencies like Central and State PWD’s, Ministry of Road Transport and Highways (MORTH), National Highway Authority (NHAI), Border Roads Organizations (BRO), Department of Science and Technology and several Public and Private sector organizations. The division also works on in-house R&D projects for a continuous development in the new areas of research. It has also contributed significantly in formulating several National codes of practices and guidelines in the area of geotechnical engineering being published by organizations such as Bureau of Indian Standards, Indian Roads Congress etc.  The division is well equipped with conventional as well as advanced testing equipments, instruments and software to undertake various kinds of laboratory and field studies in the area of geotechnical engineering related to highway investigations and research. It also offers training to highway professional in the above areas of specialization.

Pioneering work was undertaken regarding consolidation of marine clay deposits at various places in coastal areas of the country and efficacy of techniques like sand drain method, sand wick method, stone columns, pre loading technique, use of light weight fill, etc were investigated. Subsoil investigation work and design of embankment in water logged areas, difficult terrain has been undertaken for various road construction agencies. Instrumentation and monitoring of consolidation process has been carried as a part of many such projects. In the process many new instruments have been developed. In the recent past design of reinforced approach embankments and instrumentation aspects have received the special attention in the projects undertaken by GTE Division.

The other expertise of the GTE Division is ‘use of waste and marginal materials in road works’. Extensive characterisation of various waste materials like fly ash, steel plant slags, copper slag, kimberlite tailings, municipal wastes, cinder, Jarofix, etc has been done and specifications have been developed for use of these materials for construction of road embankments and road pavements. Many of these specifications have been standardised by Indian Roads Congress. Field supervision of construction using waste materials and monitoring the performance of such stretches has also been carried out. A further thrust to such activities is now being given in 12th Five Year Plan activities by taking up preparation of data-base on availability of waste and marginal materials in selected areas of the country and optimising the use of such materials for construction of roads. 

This Division has worked on the problem of mitigating landslides since its inception. Extensive data base for about 400 active landslides in the country has been prepared and land slide hazard zonation maps as well as management and mitigation strategies have been worked out. The institute has pioneered soil nailing techniques and use of jute/coir based geotextiles for stabilisation of hill slopes against landslides and erosion. These activities are now to be taken up with increased vigour in 12th FYP jointly in association with CSIR-CBRI and also with CSIR-NISCAIR.

Areas of R & D and Consultancy Activities

Geotechnical Investigations for Highway Design and Construction

  1. Sub-soil investigations for highways including minor and major bridges.
  2. Computer Aided Design/Stability Analysis of High Embankments on Normal/Soft/Expansive Soils
  3.  Failure Investigations of High Embankments and design for remedial measures.
  4. Design and construction of road embankments in flood and cyclone prone areas.
  5. Instrumentation to Monitor Settlements, Pore Water Pressure, lateral deformations and in-situ Stresses.

Ground improvement techniques

  1. Ground Improvement by Sand/band Drains, Stone Columns, Lime piles, Lime Slurry Injection etc.
  2. Mechanical and chemical soil stabilization
  3. Geo-synthetics in Roads and Embankments
  4. Coir and Jute Fabrics in Construction of Roads
  5. Design and Construction Supervision of Reinforced Earth Structures

Utilization of Waste and Marginal Materials for Road and Embankment construction

  1. Coal Ashes
  2. Iron & Steel Slags 
  3. Copper slag
  4. Super fine copper slag
  5. Zinc slag
  6. Phosphogypsum
  7. Jarosite & Jarofix
  8. Municipal wastes
  9. Kimberlite tailings
  10. Rice Husk Ash
  11. Mining wastes
  12. Red Mud
  13. Construction and demolition waste
  14. Cinder

Landslide Investigations

  1.  Hazard Zonation mapping and Management, Mitigation Measures, Instrumentation etc.
  2. Deep Trench and horizontal Drain Technique for Stabilization of landslides
  3. Design of protective measures viz. Retaining walls, Gabion and Reinforced earth walls.
  4. Soil Nailing Techniques for Stabilizing Steep Soil Slopes
  5. Erosion Control of Natural Slopes by Vegetative Turfing, using synthetic geotextiles and natural fibres like  Jute and coir fabrics.

Infrastructural facilities

Laboratory investigations

  1. Automatic sieve shaker
  2. Casagrande Test Apparatus and  Cone Penetrometer
  3. Proctor Compaction Apparatus (Standard/Modified)
  4. Direct Shear Test Assembly (Small/ Big shear box Apparatus)
  5. Triaxial Shear Test Apparatus
  6. Consolidation Test Apparatus
  7. Permeability test
  8. CBR Test Apparatus
  9. Relative density test equipment
  10. Flexural Strength Test
  11. Vane Shear Test
  12. Repeated Load Triaxial test
  13. Geosynthetic Pullout Test Facility
  14. Total Station (Electronic Theodolite)
  15. Global Positioning System
  16. Rock Cutting and Grinding Machine
  17. Rock testing
  18. Muffle furnace

Field investigations

  1. Drilling Rig Equipment
  2. Field Vane Shear Test
  3. Static Cone Penetrometer
  4. Plate load tests
  5. Dynamic Cone Penetrometer Test
  6. Electrical resistivity meter
  7. Settlement gauges, Piezometers and inclinometers

Training programme

  1. Geotechnical and Landslide Investigations for Highway Projects
  2. Planning, Design, Construction & Maintenance of Rural Roads (PMGSY)

Software Tools

  1. Software packages for geotechnical applications like sub soil investigations, High embankment design, Settlement analysis, Reinforced earth wall design, Soil nailing and designs for bearing capacity computations.

Significant achievements

  1. Detailed Geological, Geotechnical investigation, Instrumentation and monitoring of over 250 landslides in different parts of the country and suggested suitable remedial measures.
  2. Development of landslide mitigation techniques and hazard management.
  3. Design details and method statement provided for several projects for construction of high embankments & Reinforced earth retaining walls with ground improvement techniques using band drains, stone columns and geosynthetics etc.
  4. Successfully stabilised steep hilly slopes using Soil nailing and horizontal drains technique
  5. Pioneered the technique of stabilising unstable vertical cut slopes with soil nailing and construction of underpass in highly unstable soil conditions.
  6. Provided techniques and guidelines for road and embankment construction in cyclone and flood prone areas.
  7. Developed specifications for use of large number of waste and marginal materials available in India for road constructions and provided construction guidelines.
  8. Made pioneering effort in promotion of natural and synthetic geotextiles (a new construction material) in  civil engineering projects by carrying out extensive R&D efforts
  9. Prepared GIS based subsurface map of Delhi and microzonation of same for seismic hazard
  10. Contributed significantly in bringing out National Code of Practices and Guidelines

Contribution to Codes/Standards/Manual/Guidelines/Handbook

  1. State-of-the-Art-Report on Ground Improvement Vol I &II- Published by Indian Roads Congress(IRC), India
  2. State-of-the-Art-Report on Landslide Correction Techniques- Published by  Indian Roads Congress, India
  3. State-of-the-Art-Report on Geotextiles - Published by Indian Roads Congress, India
  4. Manual on Rural Road Development in India, Vol I &II- Published by Planning Commission, India
  5. Guidelines for Use of Flyash in Roads and Embankments, IRC-58 - Published by Indian Roads Congress, India
  6. Guidelines for Use of Geotextiles in Roads Pavement and Associated Works, IRC-59- Published by Indian Roads Congress, India
  7. State -of – the –Art  Report on Soil Stabilisation - Published by Indian Roads Congress, India
  8. State –of- Art Report on Bound and Unbound Granular Bases and Subbases- Published by Indian Roads Congress, India
  9. Hill Road Manual Published by IRC
  10. Guidelines on Drainage Aspect of Roads Published by IRC
  11. Guidelines for Soil and Granular Material stabilisation using Cement, Lime and Flyash, IRC:SP;89-2010, Published by IRC
  12. Recommended Practice for Construction of Earth Embankment and Subgrade for Road Works, IRC:36-2010, Published by IRC
  13. Recommended Practice for Treatment of Embankment and Hill Slopes for Erosion Control, IRC-56-2011, Published by IRC
  14. Draft Guidelines for Construction of Roads and Embankments in Cyclone Prone Area- National Disaster Management Authority
  15. State-of-art report on Use of Jute Geotextiles for Construction of Roads and Erosion Control, Published by Indian Roads Congress, India
  16. Guidelines for Review of Construction of National Highways under NHDP-Published by Indian Audit and Accounts Department