Regional Report: DFI India Beginning with this issue, Deep Foundations magazine will feature reports from DFI India, DFI Middle East and DFI Europe. This issue has a report from Dr. K.S. Rama Krishna, Head-Foundation & Geotechnical Engineering Cell (FGEC), Larsen & Toubro Ltd., Chennai, India. Dr. Ramakrishna sums up the state of deep foundations technology in India. Our next issue (March/April) will include a feature from DFI Middle East and in the June/July issue we will hear from a representative of DFI Europe. These reports might focus on trends, advances, and even controversies under discussion from their region. Some contributions may be guest editorials, and others, about an especially innovative project ongoing in the correspondent’s area. Virginia Fairweather, Executive Editor Indian Deep Foundation Industry Foundation engineering in India is probably as old as its civilization, but modern foundation engineering practice is unfortunately at a nascent stage. Even though soil mechanics and foundation engineering have been taught in our engineering institutions for several decades, professional development in engineering and construction is lagging far behind more developed nations. Many consultants in India do not have geotechnical engineers on their payroll. We hope that this situation will improve soon so that geotechnical engineers exposed to new foundation technologies can be employed by consultants and promote the latest types of foundations and geotechnical systems. The same is true about Dr. K.S. Rama Krishna Head-Foundation & Geotechnical Engineering Cell (FGEC) Larsen & Toubro Ltd., Chennai, India foundation equipment, methods and construction processes. Bored cast-in-situ piling is very common in India, even though it is not necessarily the cheapest and most effective foundation system. The slow tripod type rigs are being gradually replaced by the modern hydraulic rotary piling rigs. Thanks to the National Highways Authority of India, the Delhi Metro Rail Corporation and other client organizations who have encouraged contractors to import and deploy hydraulic rotary piling rigs at their project sites. The country now has around 1,000 rotary piling rigs and the demand for these rigs is ever increasing. Similarly it is heartening to see modern diaphragm wall equipment like hydraulic Kelly grabs and rope suspended grabs being used in metro station projects and in basement construction for multistory buildings. There are two or three trench cutters currently deployed at some dam sites for making deep cut-off walls. With more metro projects and multistory buildings being built in the next few years, we hope to see more equipment doing deep diaphragm walls in major cities. Foundation instrumentation and monitoring is another area that needs to be made mandatory in all important underground constructions to improve safety and performance. Most of the reputable piling rig manufacturers from Europe and China are active in our foundations market. We need to manufacture special foundation equipment in India to save money on freight and customs, and make prices affordable. Technologies, particularly driven precast and cast-in-situ piles could help in speeding up projects with quality and cost effectiveness. Integrated driven piling rigs with hydraulic impact hammers are also not popular in India. With India’s reasonably good highways, roads and transportation systems, there is a huge opportunity for factory made precast piles and pile splicing systems, modern driven piling equipment and installation processes. Technologies like continuous flight auger piles, deep soil mixing, and soil improvement should find more acceptance among the consultants and owners as these can accelerate construction and offer cheaper and good quality foundation alternatives. Excavator mounted foundation equipment will also have a huge potential in India as they can be procured at a lesser capital cost. Examples of these are the mass stabilization systems, rapid impact compactors, side grip vibrohammers, etc. Quality and integrity testing of foundations is one area that is slowly gaining acceptance in India with Pile Driveability Analyzer and Pile Integrity Tests becoming popular. Other forms of testing before piles are concreted using borehole camera, sonic caliper, etc., should also find their way into the Indian foundation industry. We need to increase pile diameters to more than 2,000 mm (78.7 in) particularly for metros, marine structures and multistory buildings. At the moment a 1,200 mm (47.2 in) diameter pile is considered as a big pile as most of the bored cast- in-situ piles are in the range of 600 to 900 mm (23.6 to 35.4 in) diameter. This change would lead to greater economy and speed. The latest pile load testing systems such as embedded load cells, statnamic, and instrumented load tests would replace the cumbersome and less safe kentledge type load test systems. Indian codes and design practices also need to be upgraded to promote the large diameter piles and improved monitoring and testing systems. The foundation industry also suffers from a lack of genuine interest by the young engineers in executing foundation works. Integrated piling rigs such as this Reliance KGD driving precast piles at Kakinada are rarely seen in India DEEP FOUNDATIONS • JAN/FEB 2012 • 23
