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SARATHY GEOTECH & ENGINEERING SERVICES PVT LTD (ISO 9001:2008 & OHSAS :18001:2007 CERTIFIED COMPANY)

JAN 2016

SGES - NEWS - 05 “The true sign of intelligence is not knowledge but imagination.”-Albert Einstein 1

SOIL NAILING

Soil nailing is an innovative earth retaining technique, consisting of passive reinforcement of the existing ground by the insertion of slender elements like steel reinforcing bars. Other methods of soil nailing use geotextiles, geogrids or geonets. It is best suited to enhance the performance of granular soils. It has been used even in the case of stiff clays, to improve the stability of slopes and to provide support to excavations. Soil nailing is constructed in staged excavations from top down and requires formation of a series of small cuttings generally 1-2m high in the soil. The steel bars that are used as reinforcing elements can be classified into- driven nails, grouted nails, jet grouted nails and corrosion protected nails. A shotcrete facing is then applied at the wall face in order to provide continuity. A nailed soil structure must be able to resist the outward thrust from the unreinforced soil behind without sliding, and must be stable against rotational slips. The nails must be installed in sufficient numbers with appropriate vertical and horizontal spacing and to adequate depth to ensure stability of the slope. The available analysis and design methods for soil nail walls are:

(i) Limit equilibrium design method: Global factor of safety is evaluated with respect to a rotational or translational failure along potential sliding surfaces, considering shearing, tension, and pull-out resistance of the inclusions crossing the potential failure surface.

(ii) Working stress design method: Estimating the tensile and shear forces generated in the nails during construction under the design loading conditions and evaluate the local stability at each level of nails.

Analysis of Failure Modes: For the analysis of potential failure modes of soil nail walls, allowable stress design (ASD) methodology is generally adopted. External and Internal failure modes are checked. In the external failure mode, the global stability of the soil-nail wall is checked. It refers to the overall stability of the soil-nail wall. The failure plane is assumed to be inclined at an angle with repect to the horizontal.The global stability is goverened by the following equation:

(𝐹𝐹𝐹𝐹𝐺𝐺)𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜 𝑠𝑠𝑠𝑠𝑜𝑜𝑠𝑠𝑠𝑠𝑜𝑜𝑠𝑠𝑠𝑠𝑠𝑠 =∑𝑅𝑅(𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅 𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝑅𝑅𝑅𝑅)∑𝐷𝐷(𝐷𝐷𝐹𝐹𝑅𝑅𝐷𝐷𝑅𝑅𝑅𝑅𝑅𝑅 𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝑅𝑅𝑅𝑅)

The second aspect in external failure mode is sliding stability. The ability of the soil nail wall to resist the sliding along the base of the retained system in response to lateral earth pressures behind the soil nails is considered for analysis. When the additional lateral earth pressures exceed the sliding resistance, failure occurs. The factor of safety for this criteria is calculated by the following equation:

(𝐹𝐹𝐹𝐹𝐺𝐺)𝑠𝑠𝑜𝑜𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠 𝑠𝑠𝑠𝑠𝑜𝑜𝑠𝑠𝑠𝑠𝑜𝑜𝑠𝑠𝑠𝑠𝑠𝑠 =∑𝑅𝑅(𝐻𝐻𝐹𝐹𝐹𝐹𝑅𝑅𝐻𝐻𝐹𝐹𝑅𝑅𝑅𝑅𝐻𝐻𝐻𝐻 𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅 𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝑅𝑅𝑅𝑅)

∑𝐷𝐷(𝐴𝐴𝐴𝐴𝐴𝐴𝐻𝐻𝑅𝑅𝑅𝑅𝐴𝐴 𝐷𝐷𝐹𝐹𝑅𝑅𝐷𝐷𝑅𝑅𝑅𝑅𝑅𝑅 𝐻𝐻𝐹𝐹𝐹𝐹𝑅𝑅𝐻𝐻𝐹𝐹𝑅𝑅𝑅𝑅𝐻𝐻𝐻𝐻 𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝑅𝑅𝑅𝑅)


JAN 2016

SGES - NEWS - 05 “The cure for boredom is curiosity. There is no cure for curiosity.” Ellen Par 2

The second part of the analysis of failure mode is the Internal Stability of soil nails. The stability is checked at each nail level. The significant aspect being pullout failure For the soil nail pullout failure mode, the failure occurs along the soil-grout or soil-nail owing to insufficient intrinsic bond strength or insufficient nail strength. The factor of safety against pull out failure can be estimated for any specific nail embedded at depth ‘z’ by:

(𝐹𝐹𝐹𝐹𝑃𝑃)𝑍𝑍 = �𝑅𝑅𝑃𝑃(𝑃𝑃𝑃𝑃𝐻𝐻𝐻𝐻𝐹𝐹𝑃𝑃𝑅𝑅 𝐶𝐶𝐻𝐻𝐴𝐴𝐻𝐻𝐹𝐹𝑅𝑅𝑅𝑅𝐶𝐶)

𝑇𝑇𝑍𝑍(𝑀𝑀𝐻𝐻𝑀𝑀𝑅𝑅𝑀𝑀𝑃𝑃𝑀𝑀 𝐴𝐴𝑀𝑀𝑅𝑅𝐻𝐻𝐻𝐻 𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝑅𝑅 𝐷𝐷𝑅𝑅𝐷𝐷𝑅𝑅𝐻𝐻𝐹𝐹𝐴𝐴𝑅𝑅𝐴𝐴 𝑅𝑅𝑅𝑅 𝑅𝑅ℎ𝑅𝑅 𝑁𝑁𝐻𝐻𝑅𝑅𝐻𝐻)�𝑍𝑍

SGES have capabilities to provide design and build services for soil nailing and

other ground improvement technique

Boundary Wall

50mm Thick Shotcrete

4m

7m

1m 2m

0.5m

Filled up Soil 4m

Driven Nails 8m length and 20mm dia. @ 0.4m c/c

Sandy Clay

Silty Sand

PVC pipes at 3m c/c

SGES have capabilities to provide design and build services for soil nailing and other ground improvement techniques


JAN 2016

SGES - NEWS - 05 “We are made wise not by the recollection of our past but by the responsibility of our future.”

George Bernard Shaw 3

. EVENTS AND MILESTONES IN 2015 (3rd AND 4th Quarter)

1. SGES participated in EXPO organised by Engineering Export Promotion Council of India (EEPC), held at Mumbai in November 2015.

2. Dr CR Parthasarathy delivered a lecture at Amrita University, Coimbatore in Sept 2015. 3. His Holiness Sri Subhudendra Teertha Swami of Sri Raghavendra Swami Mutt,

Mantralayam visited SGES office on 15th December 2015. 4. SGES participated in Micro Small Medium Scale Enterprises (MSME) IND EXPO, held at

Bangalore. 5. SGES sponsored Deep Foundations Technlogies for Infrastructure Development in India

Conference, held at Indian Institute of Science, Bangalore in September 2015. SGES team- Dr.Prashanth Talkad, Ms. Meera Jacob and Mr.Manilal Gupta attended the conference.

6. Vision 2020 and all hands meet of SGES at Bangalore in December 2015. 7. SGES Team successfully completed pile montoring for the installation of New Jetty 2 for

UMM QASR Marine Terminal, Iraq. 8. SGES has completed Design and build support system for 14m deep excavation at

Prestige west Wood project. 9. SGES featured in Dun & Bradstreet publication as one of the leading SMEs of India in 2015.

AWARDS AND RECOGNITIONS:-

• Fastest Growing Company in Geotechnical Engineering 2015 at the 6th Annual India Leadership Conclave & Business Leadership Awards 2015, Mumbai.

• Entrepreneur of the Year 2015 awarded to Dr CR Parthasarathy at the 6th Annual India Leadership Conclave & Business Leadership Awards 2015, Mumbai.

• Mahatma Gandhi Gourav Sanman-2015 awarded to Dr CR Parthasarathy for outstanding individual achievements and distinguished service to the nation.

• Best Geotechnical Engineering Services Provider Company in South India, 2015

awarded to SGES by PRIMETIME.

• SGES is awarded SOUTH REIGONAL EXPORT AWARD by Engineering Export Promotion Council of India (EEPC).

Employees Speak:- “SGES is a highly focused company and is very clear about its vision and mission. It’s been 8 years that I have been working in SGES and it has proved to be a good experience for me. I have been able to develop myself both ‘personally and professionally’. SGES is a nice place to work with colleagues and supervisors always ready to provide their support. I have always had opportunities and challenges beyond my current role to prove myself and achieve greater heights”. - Harsha Kadiyali (Project Manager, SGES) “Right from the start of my career at SGES, I have been blessed to be guided by a great team. It is a never ending learning experience for me and facing new challenges everyday keeps me motivated and be innovative”.- Anusha Bekal (Senior Engineer - Proposals & Quality Management,SGES)


JAN 2016

SGES - NEWS - 05 “We are what we repeatedly do; excellence then, is not an act, but a habit.”

Aristotle 4

SGES STAFF AT NIGERIA DANGOTE PROJECT DFI CONFERENCE, IISc, BANGALORE

MAHATHMA GANDHI GOURAV SANMAN REGIONAL EXPORT AWARD BY EEPC

INDIA

HIS HOLINESS SRI SUBHUDENDRA TEERTHA SWAMI AT SGES OFFICE IN DECEMBER 2015

BEST GEOTECHNICAL ENGINEERING SERVICE COMPANY IN SOUTH INDIA-2015

BY PRIME TIME. AWARD RECEIVED BY Mr. MANILAL GUPTA

TEAM SGES AT EEPC EXPO, MUMBAI NOVEMBER 2015


JAN 2016

SGES - NEWS - 05 “Excellence is a continuous process and not an accident.”

A.P.J.Abdul Kalam 5

HAPPENINGS IN 2016 1. Complete Geotechnical Investigation for M/s. Dangote in Nigeria. 2. SGES will be carrying out the Offshore Pile Monitoring for Vasai Project of ONGC in

February 2016. 3. Dr CR Parthasarathy will be delivering a lecture at the Seminar “New Construction

Technology and Construction Techniques in MES Works on 12 February 2016. 4. SGES Engineers Ms. Meera Jacob and Ms. Pratibha Ramesh will be attending short

course on Tunneling, 15 to 18 March 2016 at New Delhi. Course organized by Dr Manoj Verman – Tunneling and Rock Engineering Expert.

5. SGES is planning to Complete NABL Accreditation process for the laboratory by mid of 2016.

6. Dr CR Parthasarathy will be attending 2nd Myanmar Offshore Summit 2016, in Yangon, Myanmar on 30 and 31 March 2016.

7. SGES is planning to upgrade the QMS to ISO 9001: 2015.

TEAM SGES IN IND EXPO AT MSME,

BANGALORE JANUARY 2016

TEAM SGES AT EEPC EXPO, MUMBAI

NOVEMBER 2015

Dr. C R PARTHASARATHY DELIVERED A TECHNICAL LECTURE AT AMRITA UNIVERSITY, COIMBATORE


JAN 2016

SGES - NEWS - 05 “Excellence is a continuous process and not an accident.”

A.P.J.Abdul Kalam 6

THE SGES TEAM – ALL HANDS MEET IN DECEMBER 2015 @ BANGALORE

Registered and Communication Office: Geotechnical Laboratory & Operations Office:

SARATHY GEOTECH & ENGINEERING SERVICES PVT LTD # 671, 6th C Main, 11th Cross, 3rd Phase JP Nagar, Bangalore – 560078 Tel: +91-80-42850202

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Wish you all a very happy and prosperous New Year 2016

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