Dossier on Ipis
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IN PLACE INCLINOMETER APPLICATION DOSSIER Msheireb Station (Package 5), Major Project Stations, Doha Metro Location Doha, Qatar Client Qatar Rail Company Samsung C&T - Obrascon Huarte - Qatar Building Co. JV (SOQ JV) - 2013 to 2016 Contractor Consolidated Contractors Group S.A.L - 2016- 2019 The Louis Berger Egis Rail Joint Venture Consultants (LBER JV) Duration 2013 - 2019 Project overview Key data on IPIs Doha Metro is the world’s largest infrastructure project. Eighty- • A total of 14 no. IPIs were installed two km of metro tunnel incorporating 26 stations will run in Msheireb station-10 no. in underground in Phase 1. Msheireb Station will serve as the diaphragm wall of the station box heart of Phase 1 as it is the major interchange station of three and 4 no. in soil behind the wall. metro lines – with Red and Green Lines running parallel and Gage length of IPIs was 3m. Gold Line situated underneath. It is the largest underground • Up to 13 no. biaxial SDI-12 tilt station in Doha situated at the corner of Msheireb Downtown sensors were installed a in a single Doha development. The station lies between ~ 15 m to 40 m inclinometer gage well. below ground level. • Gage wells were constructed of 70 The Msheireb Station in the centre of the metro already forms mm o.d. ABS grooved casing up to the accumulation point of the whole system. All lines meet 42 m deep. here, 12 TBM breakthroughs ended at this mammoth station alone. Excavation for Msheireb Station, approximately 40 m • In diaphragm wall, gage wells were below ground level is one of the deepest excavations for metro constructed within protective GI in the Middle East, therefore, Instrumentation & Monitoring pipe cast in d-wall. (I&M) played an important role in the project. I&M scheme • Logging was done automatically implemented by Encardio-rite was a mix of automatic and with a frequency of once in 2 hours. manual monitoring. In place inclinometers were a key component of the automatic monitoring and gave vital • Data was available on the project’s information on diaphragm wall deformations. web-based data monitoring service in real-time with automatic e-mail alerts. www.encardio.com INDIA: LUCKNOW | DELHI | KOLKATA | MUMBAI | CHENNAI | BANGALORE | HYDERABAD | J&K INTERNATIONAL: UAE | QATAR | BAHRAIN | GREECE | SINGAPORE | BHUTAN IN PLACE INCLINOMETER APPLICATION DOSSIER BAHRAIN Cabo Raj Bhavan (Governor’s House) Project Slope stability of Cabo Hill Location Goa, India Client Water Resources Department Contractor ITD Cementation Consultants Geological Survey of India (GSI) Duration 2007 - 2017 Project overview Key data on IPIs Cabo Fort which houses the present Governor’s house or Raj • A total of 9 no. IPIs were installed Bhawan in Goa was built around 1540 AD to guard the for slope monitoring. entrance to both the Mandovi and Zuari rivers. Cabo fort is the • The IPIs were installed in gage finest of the Raj Bhavans in India. wells constructed from 70 mm o.d. The fort is located on Cabo Hill at a height of 40 m above the ABS inclinometer casing, sea. It is a two-storied monumental structure constructed with • Gage length of the IPIs was 2 m. 0.7 m thick walls comprising of laterite blocks in mud mortar. • Up to 12 no. SDI-12 bi-axial tilt The hill slope was reported to have been undergoing a gradual sensors were used in a single gage distress due to natural processes over several decades with well cracks appearing on the asphalted pavement in front of Chapel and on the floor of the verandah. The parapet wall constructed • Average depth of gage well was 24 around the edge of the steep slope adjacent to the Raj Bhavan m. had also developed cracks at many places indicative of • Automatic logging of IPIs was done horizontal and lateral movement. twice per day in the rainy seasons May to September and in the rest, The upper part of the slope was stabilized by using pre- once per day. The data was stressed cable to tie up the fractured, hard lateritic media. The available on-line in real-time middle part of the slope was stabilized by installing shear Encardio-rite’s web-based data interceptors using micro piles. Vertical sand piles were also monitoring service. provided to release the possible groundwater pressure. The toe part of the slope was stabilized with retaining walls. To monitor the distressed unstable slopes of Cabo Hill, GSI recommended field monitoring through instrumentation. The instrumentation scheme included monitoring of slope movement, settlement, water pressure and ground cracks. In place inclinometers played an important role in monitoring slope deformations. Key data on IPIs www.encardio.com Over 50 years of excellence through ingenuity IN PLACE INCLINOMETER APPLICATION DOSSIER BAHRAIN Project Plot-13 Deira Waterfront Development Location Dubai, UAE Deira Waterfront Development L.L.C/ Client Investment Corporation of Dubai Dutch Foundation & Concrete Processing Contractor Company Consultants Coffey, COWI, Parsons Duration 36 month from May 2016 Project overview Key data on IPIs Deira Waterfront Development encompasses an expansion of • Eleven no. IPIs were installed for the urban fabric to the existing Deira community. It is one of the monitoring existing Green Line most important development projects and involves the Metro tunnel, gage length 2 m, with construction of a number of new plazas, mixed-use buildings up to 9 no. sensors in one gage and green open spaces. The project aims to develop the well. seafront which will be unique and beautiful. • Three no. IPIs were installed for monitoring existing Shindagha Phase 1 of the project includes the development of almost 30 Road tunnel, gage length 2 m, with plots along the waterfront, each plot having its own 10 sensors in each gage well. development and design. Plot-13 is located in the northern portion of Dubai in the Deira District. The proposed Mixed Used • Biaxial SDI-12 tilt sensors were Development at Plot 13 includes a maximum two-level used in both sites. basement (approximately 10 m deep excavation) and is • ABS grooved casing of 70 mm situated between the Al Shindagha tunnel and Dubai Metro diameter was used to construct the Green Line tunnel. gage well. The nearest edge of the shoring works was at 10 m from the • Automatic logging at every 4 hours Dubai Metro Green Line tunnel and the south-eastern edge with real-time display on Encardio- was located at a distance of 15 m from the existing Al rite’s web-based data monitoring service. Shindagha Road tunnel. • Automatic e-mail alters to project’s As the project involved heavy construction activities quite stakeholders and construction team adjacent to tunnels, monitoring became necessary for safety of on breach of trigger values. the two existing tunnels. IPIs were used for monitoring subsurface lateral movements which may affect the existing tunnels due to excavation and dewatering activities. www.encardio.com Over 50 years of excellence through ingenuity IN PLACE INCLINOMETER APPLICATION DOSSIER Note on excessive movements recorded by an IPI Progressive movements were noted in one of the in-place inclinometers (IPI) installed in the shoring wall in the vicinity of the Shindagha tunnel (refer to figure below). Upon breach of trigger level, to verify the readings, the IPI chain was removed. Subsequently, the readings were continued with the same manual inclinometer system, using which baseline reading of the inclinometer was established prior to installation of the IPI chain. The results confirmed the IPI’s behavior to a great extent. Readings collected from survey targets installed in the same section of the inclinometer on the shoring wall also confirmed the movements recorded. The contractor took preventive measures by providing additional anchoring and horizontal support at the section of the shoring system showing excessive deformation, based on the monitoring results. Upon further analysis of the cause of deformation, the recharge method using pressure jetting deployed at the site was determined to be the factor contributing to the deformations observed. It was also observed that the standpipe piezometer’s trigger limits, breach of which was the reason behind the recharging were also at the fault. www.encardio.com INDIA: LUCKNOW | DELHI | KOLKATA | MUMBAI | CHENNAI | BANGALORE | HYDERABAD | J&K INTERNATIONAL: UAE | QATAR | BAHRAIN | GREECE | SINGAPORE | BHUTAN .