ABSTRACT:

As structures get taller and the load demand on the foundation soils increases, it has become imperative to reconsider conventional geotechnics, and calibrate and validate our theoretical predictions with ground conditions. A prototype footing load test was conducted on a 2 m x 2 m size concrete footing for a better assessment of the load-settlement behavior at a site in Noida. This paper presents the test results and compares them to results from conventional methods of analysis. A numerical simulation of the test conditions has also been performed using finite element method to validate the field results with mathematical simulation. It has been found the results of the field test are in good agreement with theoretical predictions, thus enhancing the factor of reliability of our foundation analysis.

Citation : Sanjay Gupta, Ravi Sundaram, Sorabh Gupta (2016), “Footing Load Tests on Sand: Validating Theoretical Predictions”, Proceedings, Indian Geotechnical Conference-IGC-2016, Chennai

 

Abstract: Reliability of improvement achieved is the key to the implementation of soil stabilization and ground improvement measures. In-situ tests are an essential part of the ground improvement process to confirm that the desired improvement in soil properties has been achieved. The paper presents two case studies in the Delhi-NCR area where ground improvement was done to mitigate liquefaction potential and improve the soil bearing capacity. In-situ tests conducted before and after improvement to verify the effectiveness of improvement include SPT (in boreholes), static cone penetration tests (SCPT) and plate load tests.

Citation: Ravi Sundaram, Sanjay Gupta (2015), “In-Situ Testing to Verify Ground Improvement”, Proceedings, Symposium on “Advances in Instrumentation, Geo-Monitoring and Validation”, 23-24 July, 2015), New Delhi

Abstract : Evaluating the depth of existing foundations may sometimes be required on construction projects. If original pile records / drawings are not available, it may become difficult to make a rational assessment of the depth of existing foundations. Where the new construction requires knowledge of length of pile / depth of existing foundation, modern NDT techniques such as parallel seismic and sonic echo / impulse response tests can provide useful information.

Citation :Sanjay Gupta, Ravi Sundaram, Sorabh Gupta (2015), “NDT Techniques for Determining Depth of Foundations”, Proceedings of 50th Indian Geotechnical Conference (December 17-19, 2015), Pune, Maharashtra,

Abstract: Caution is required in selecting the safe load carrying capacity of bored piles, even if a few test piles indicate substantially higher capacity than theoretically estimated from static analysis. The consequences of failure of working piles should be evaluated carefully to select suitable safe load carrying capacity for design. Use of pile capacities higher than the computed values should be backed up by sufficient static and dynamic pile load tests and integrity tests. A case study illustrating static and dynamic load tests on piles installed in alluvial sands demonstrates the design methodology to be followed.

Citation : Ravi Sundaram, Sorabh Gupta (2015), “Back-Analysis Of Pile Load Test Results – A Case Study”, Proceedings, Symposium on “Advances in Instrumentation, Geo-Monitoring and Validation”, 23-24 July, 2015), New Delhi

 

Summary : Geotechnical investigation through gravel-boulder formations poses difficulties due to the problems of drilling in such deposits. Various drilling methods such as percussion, rotary and DTH have been used on projects with different degree of success; a combination of two methods is usually effective. In addition to drilling, geophysical tests and load tests help in better assessing the stratigraphy and selecting suitable values of safe bearing capacities.

Citation : Sundaram, Sanjay Gupta (2016), “Geotechnical Investigation in Gravel-Boulder Deposits”, The Bridge & Structural Engineer, Journal of the Indian National Group of International Association for Bridge and Structural Engineering, B&SE (December, 2015), Volume-45, No. 4.

Abstract :A major University site spanning 511 acres with a total constructed area of 357 acres has recently been constructed in the state of Uttar Pradesh in north India. The campus, once established, shall boast of over 84,000 m2 of constructed area with 30 percent green cover. The site is located in the Yamuna flood plain, about 2 km. from the river.

Citation: Ravi Sundaram, Sanjay Gupta, Sorabh Gupta (2014), “Building a University on Liquefiable Soils Using Dynamic Compaction”, Proceedings of DFI Conference (September 19-20, 2014), Delhi, Page 67.

Introduction : Construction of deep bored piles requires adequate quality assurance measures to ensure that the pile is free of major defects and can safely carry the design loads. The paper presents pile quality assurance tests implemented for two case studies of large diameter piles installed in the Indo-Gangetic Alluvium.

Citation : Ravi Sundaram, Sorabh Gupta (2014), “Identifying Defects in Large Diameter Bored Piles – Case Studies”, Proceedings of DFI India Conference (September 19-20, 2014), Delhi Page 44

Introduction :If the Twelfth Plan (2012-17) estimates of Over $1 trillion investment in infrastructure development fructify, it will present an enormous opportunity for the construction industry, and specifically for foundation and piling works. Construction is critical to infrastructure project development and, typically, 5 per cent or more of the cost of any civil engineering project in India is contributed by foundations and piling. The key market segments for foundation and piling works include roads and highways, power plants, marine structures, metro rail projcts, oil refineries, wate and stormwater drainage projects, airports, and comercial buildings and housing projects. \n\nThe Indian piling equipment market is estimated to be worth Rs.2 billion. The market has grown at a rate of about 20-25 per cent in the last few years, spurred by infrastructure development. However, the Indian market is still considered to be nascent and it is estimated that only about 200 piling-rela

Abstract : One of India’s tallest residential towers is being constructed in the state of Uttar Pradesh, not very far from the YamunaRiver. The development includes the construction of a 66-story residential tower rising about 240 meters above grade and having two basements extending about 9 meters below grade. The foundation system for the proposed development consists of a piled-raft system with a 2.5-meter thick reinforced raft, supported by 298 Nos. bored-cast-in-situ piles of 1 m diameter and 48 m depth. This paper describes the geotechnical investigations carried out at the project site to estimate the safe pile capacities, and presents the results of a rigorous quality assurance program executed by the authors to ensure foundation quality and performance in-situ.

Citation : Sanjay Gupta, Ravi Sundaram, Sorabh Gupta (2012), “Quality Assurance for Deep Bored Piles–A Case Study”, Proceedings of Indian Geotechnical Conference (December 13-15, 2012), Delhi Page 608 to 611.

 

Abstract : Geotechnical investigation for a major power plant in Punjab indicated the likelihood of liquefaction of the loose sands to about 7.5-11 m depth. To mitigate the liquefaction potential, ground improvement by vibro-compaction was done for the light to medium loaded facilities. Piles extending well below the liquefiable zone were used to support heavily loaded facilities. The paper presents data and analysis for the Boiler-I area where ground improvement was done successfully done and raft foundation for the raft was provided.

Citation : Sanjay Gupta, Ravi Sundaram, Sorabh Gupta (2012), “Building A Mega Power Plant On Liquefiable Sands – A Case Study”, Proceedings of Indian Geotechnical Conference (December 13-15, 2012), Delhi, Page 428 to 431.

Abstract : Soft under-consolidated clay is encountered to substantial depth in the Godavari Delta of coastal Andhra Pradesh. Constructing foundations in such weak deposits needs careful assessment of the geotechnical properties. This paper presents details of geotechnical investigations carried out for an onshore gas terminal project in such strata, an evaluation of the ground improvement methods employed at the site, and details of the selection and testing of the foundation system adopted for statically and dynamically-loaded facilities.

Citation :  Sanjay Gupta, Ravi Sundaram, Sorabh Gupta (2011), “Geotechnical Characterization Of Soft Clays Of The Godavari Delta”, Proceedings, Indian Geotechnical Conference (IGC, Dec-15-17, 2011), Kochi, pp 166 to 169.

Abstract : The paper presents the case study of liquefaction studies for an upcoming power plant in the Indo-Gangetic plain. Geotechnical site characterization studies suggested that the sands to 8 m depth were prone to liquefaction during the design earthquake. Accordingly, TG, chimney and other heavily-loaded facilities were supported on piles extending well below the liquefiable zone. Ground improvement by vibro-replacement was done in other areas of the site to mitigate the liquefaction potential.

Citation :Sanjay Gupta, Ravi Sundaram, (2011), “Liquefaction Risk Mitigation for a Power Plant in the Indo-Gangetic Alluvium”, Proceedings, The 14th Asian Regional Conference on Soil Mechanics and Geotechnical Engineering Hong Kong, China (May-2011), Page 306.

 

Introduction : Red mud is a waste product of the aluminium industry formed by washing and purifying bauxite (aluminium ore). It is pumped in slurry form into a disposal pond. Over a period of time, as the water partly seeps into the ground and partly evaporates. The red mud slurry thickens to form a soft deposit with very low SPT values.

The paper shall present the case study of an industrial structure (drum filter plant of the aluminium plant) constructed on a thick red mud deposit. Since the red mud behaves like very soft clay with SPT values in the range of 1 to 5, ground improvement was done by provision of rammed stone columns. This resulted in substantial savings to the owner in comparison to the cost for installing concrete piles.

Citation : Ravi Sundaram and Sanjay Gupta (2010), “Construction Foundations on Red Mud”, Proceedings, 6th International Congress on Environmental Geotechnics, New Delhi, Volume-II, pp 1172-1175.

Abstract: At a project site in Greater Noida (U.P.), loose to medium dense ‘clean’ Yamuna sands were encountered, which were found to be susceptible to liquefaction to about 8-12 m depth. Dynamic compaction was carried out across the entire site to densify the soils and mitigate the risk of liquefaction. Field tests (including standard penetration tests and static cone penetration tests) carried out before and after dynamic compaction indicated that the ground improvement has been successful to the desired depth. Open foundations bearing on the improved ground could now be provided in place of piles, resulting in enormous cost-saving for the owner.

Citation : Sanjay Gupta, Ravi Sundaram, Sorabh Gupta (2010), “Dynamic Compaction to Mitigate Liquefaction Potential”, Proceedings, Indian Geotechnical Conference (IGC-2010), Mumbai, Volume-II, pp 783-786.

Abstract:Large diameter cylindrical welded steel tanks bearing on soft clay deposits can experience substantial settlement. Ground improvement by provision of granular piles is an effective method to strengthen the soft clay and control settlements within acceptable limits. The paper presents the installation technique together with results of load tests conducted on trial granular piles to assess the behavior of the improved ground. The tank performance, evaluated by hydro-testing the tank, compared well with the theoretical model used to compute the settlement of the improved ground

Citation :Gopal Ranjan, Ravi Sundaram and Sanjay Gupta (2009), “Performance of a Large Diameter Oil Storage Tank on Improved Clay Deposit”, Proceedings, 17th International Conference on Soil Mechanics & Geotechnical Engineering (17th ICSMGE-2009), Alexandria, Egypt.

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.

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.

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.