Knowledge Center

At Cengrs, one of our core values is sharing of knowledge. Owing to our extensive experience in providing expert Geo-technical engineering services to the construction industry, we have over the years, gained significant knowledge about the key issues and challenges in this domain. To consolidate this valuable learning, we have established a Knowledge Centre, which primarily works on the theology of collating information & experiences, and disseminating it to interested organizations & individuals.

Through case studies and technical papers, our Knowledge Centre aims to serve as an excellent resource for anyone conducting Geo-technical activities. We strongly believe that this knowledge should be constantly refreshed and improved to provide companies with the required guidance & support for enhancing business processes and improving efficiency.

Book edited by our Director

Springer, a reputed international publisher of technicl books, has published the book "Geotechnics for Transportation Infrastructure" edited by Ravi Sundaram, J.T. Shahu and V. Havanagi in two volumes.
The two volumes are a compilation of latest research and development on geotechnical aspects of design, construction, maintenance, monitoring and upgrading of roads, railways, metro-lines and other transportation infrastructure. 
Hopefully, the contribution by the various authors will lead to a better understanding of the subject, making this publication a valuable treatise on Transportation Geotechnics.

We have three interesting papers in the book covering various aspects of field geotechnical engineering.
See the links below:
Vol 1: https://www.springer.com/gp/book/9789811367007
Vol 2: https://www.springer.com/gp/book/9789811367120

 Cengrs is commited to technical excellence and professionalism in geotechnical practice. The book is one step in that direction 

Video Presentations

Mr. Ravi Sundaram delivered a Webinar Lecture titled "Geotechnical Investigations in Difficult Ground Conditions - Field Experiences" on 18th June 2020. The lecture was organized by the Indian Geotechnical Society Guntur Chapter through its Students Chapter at the Malineni  Perumalu Educational Society's group of institutions. Attended by over 150 persoms from all over India, the lecture was very well received by the geotechnical fraternity.

In his lecture, Mr. Ravi Sundaram emphasized on the need for thorough geotechnical investigations and use of advanced testing technologies to overcome complex geotechnical challenges. He presented three case studies as given below:

  1. Soft Clays in Kochi, Kerala
  2. Boulder -gravel deposits in foothills of the Himalayas
  3. Artesian conditions in the terai regions of the Indo-Nepal border.

You may watch the lecture by clicking on the following link:

https://youtu.be/ws3zGRsmsNo

TECHNICAL PAPERS
Cement Grouting in Delhi Silt - A Field Study
Sanjay Gupta, Ravi Sundaram, T. Ramamurthy & S.N. Sinha, 15-Jun-1997

SYNOPSIS : Loose alluvial sites of Delhi can be successfully grouted using cement slurry. The paper presents a case study wherein the cement grouting was done to strengthen the foundations of a three storeyed building bearing on loose “Delhi Silt”. Details of the pressure grouting are presented together with the grout consumptions at various intake points. After grouting, the building was load tested to confirm the efficacy of the ground improvement.

Citation : Sanjay Gupta, Ravi Sundaram, T. Ramamurthy & S.N. Sinha (1997), Cement Grouting in Delhi Silt - A Field Study, Proceedings, Indian Geotechnical Conference, IGC - 97, Baroda, pp 255 - 258.

 

Gravel Piles: Construction and Field Testing
Sanjay Gupta and Ravi Sundaram, 19-Apr-1996

Abstract: Construction methodology for installation of gravel piles by the non-displacement technique (i.e. boring method) is discussed in the paper. Two case studies are also presented. The first one illustrates successful application in loose sandy strata at a site in the Indo-Genetic Alluvium. At this site, 400 mm dia stone columns were used to improve the soil beneath 22 m dia tanks. Load tests using different spacing between trial stone columns was used to optimize the design. The second case study relates to stone columns installed in marine clay in coastal Andhra Pradesh.

Citation : Sanjay Gupta and Ravi Sundaram (1996), Gravel Piles: Construction and Field Testing, Proceedings, Seminar on Piles, Indian Geotechnical Society, Delhi Chapter, pp 72-81.

Dynamic Characteristics of Collapsible Aeolian Sands
Ravi Sundaram and Sanjay Gupta, 05-May-1995

Synopsis: Forced vibration tests were conducted as per IS 5249 at a site in north-western Rajasthan. The soil at the site are meta-stable aeolian sands, piled up in the form of sand dunes. The test results indicate that, at shallow depths, in the loose to medium dense sands which are in the unstable part of the dune, the response under dynamic loading is poor. The two peaks in the amplitude-versus frequency curve suggest that the soil structure was probably collapsing and the sands were re-arranging into a more compact state. Tests were also conducted on the deeper relatively more stable soils. The test results were effectively used to design dynamically loaded foundations.

Citation : Ravi Sundaram and Sanjay Gupta (1995), Dynamic Characteristics of Collapsible Aeolian Sands, Proceedings, Indian Geotechnical Conference, IGC-95 Bangalore, pp 387-389.

Small Diameter Rammed Stone Columns in Fine Sands
Ravi Sundaram and Sanjay Gupta, 26-Jun-1994

Synopsis: The advantage of small diameter reamed stone columns is that they can be installed using simple augers and a small compaction winch. Thus, rammed stone columns may often work out as a cheaper alternative to pile foundations. It can cause substantial reduction in foundation settlement, thus making it an effective ground improvement technique. The paper illustrates use of the technique for improving performance of foundations on loose alluvial sands. Case studies from two sites are presented wherein the sands to about 3 to 5 m depth were loose in condition; hence the allowable bearing pressure for the specified settlement was very low. Rammed stone columns of 300mm diameter and 5 to 6 m length were installed which successfully improved the allowable bearing pressure for open foundations by reducing settlements. Plate load tests using a 1m square test plate have been used to demonstrate the efficacy of the method. The spacing between the stone columns can be adjusted and optimized to match the loading conditions and extent of improvement desired.

Citation :  Ravi Sundaram and Sanjay Gupta (1994), Small Diameter Rammed Stone Columns in Fine Sands, Proceedings, Indian Geotechnical Conference, IGC-94 Warangal, pp 345-348.

Pile Foundations Save Transmission Towers at Agra
Sanjay Gupta & Ravi Sundaram, 02-May-1994

Abstract: The shfting of course of the Yamuna River at Agra by over 800 m during the last four years had threatedned the stabililty of transmission towers of a 220 KV - transmission line on the river bank. After last year\'s monsoons, the river had shifted dangerously close to the existing towers.\n \nCengrs Geotechnica Pvt. Ltd. was awarded the design and construction contract for providing deep pile foundations for the towers that extended below the level of maximum scour. In order to ensure minimum disruption of poer supply, the new towers were first installed and then charged, after which teh existing towers were dismantlled.

Citation : Sanjay Gupta and Ravi Sundaram (1994), Pile Foundations Save Transmission Towers at Agra, Civil Engineering and Civil Construction Review, August, 1994, pp 45-46.

Recent Trends in Foundation Strengthening
Sanjay Gupta and Ravi Sundaram, 05-Apr-1992

Synopsis: Modern foundation engineering can come to the rescue of structures that have experienced significant foundation distress or failure. Detailed investigation of cause and mode of failure together with careful planning and sound engineering practice is the key to successful execution of the foundation strengthening process. Specific case histories of some projects in Delhi and Bihar are described explaining the nature of foundation distress and methodology adopted to stabilize the structures and ensuring adequate foundation performance.

Citation : Sanjay Gupta and Ravi Sundaram (1992), Recent Trends in Foundation Strengthening, Civil Engineering and Civil Construction Review, October, 1992, pp 31-33.

For which Soil Conditions are Under-Reamed Pile Foundations Superior to Other Foundation Systems
Sanjay Gupta, 25-May-1986

Synopsis: This paper discusses situations where under-reamed pile foundations have been effectively used and found to be superior to other foundation types. The use of under-reamed piles, which are conventionally considered suitable for expansive clays, have been extended effectively over the past several years to the other soil conditions also. The use of these piles is largely a function of economy, time factors, site constraints etc. Some of the projects in Delhi and other areas where under-reamed piles have been used are discussed in brief.

Citation : Sanjay Gupta (1986), For which Soil Conditions are Under-Reamed Pile Foundations Superior to Other Foundation Systems, Proceedings, Indian Geotechnical Conference, IGC-1986, Synthesis Paper Vol.III pp 97-101.

How Best Can One Estimate the Load Carrying Capacity of Piles Which Support Offshore Structures?
Ravi Sundaram, N. Ahmad, 28-May-1986

Synopsis : The evaluation of capacity of offshore piles should be a continual process. After the pile capacity has been computed in the design office, the capacities should be verified and re-evaluated in the field using dynamic pile monitoring techniques. The design should allow for revising the pile capacity based on a detailed study of the driving data. A database of offshore pile installation experience should be accumulated so as to advance the state-of-the-art in the Indian offshore areas.

Citation : Ravi Sundaram and Niaz Ahmad (1986), How Best Can One Estimate the Load Carrying Capacity of Piles Which Support Offshore Structures, Proceedings, Indian Geotechnical Conference, IGC-1986, Response Paper Vol.II, 183-186.

ARTICLES
Recent Trend In Foundation Strengthening
Sanjay Gupta,Ravi Sundaram, 01-Oct-2017

Brief:Modern Foundation engineering can come to rescue of structures that have experienced signinficant foundation distress or failure.Detailed investigation of cause and mode of failure together with careful planning and sound engineering practice is the key to successful execution of the foundation strengthening process.Specific case histories of some projects in Delhi and Bihar are described explaining the nature of foundation distress and methodology adopted to stabilize the structures and ensuring adequate foundation Performance.

Pile Foundations Save Transmission Towers At Agra
Sanjay Gupta,Ravi Sundaram, 06-Sep-2017

Brief:The shifting of course of the Yamuna River at Agra by over 800 m during the last four years had threatened the stability of transmission towers of a 220 KV-tansmission line on the river bank.After last year's monsoons ,the river had shifted dangerously close to the existing towers.

Geotechnical Investigations - The Way Forward
Sanjay Gupta,Ravi Sundaram, 19-Sep-2017

Brief:A thorough geotechnical investigation is a pre-requisite for a reliable,safe and economical foundation design.It is important that whatever is envisaged at the investigation and design stage should translate into construction that is in sync with the design concepts,assumptions and predicted foundation behaviour.