Nagpur, the second capital of Maharashtra and one of the fastest developing city in India is witnessing major growth in terms of Infrastructure. The development encompasses primarily the connectivity, of which Metro rail becomes a major part.

Incepted in 2016, the metro project is being a subject of acclaimed discussion for its speed of execution and the quality of construction.

Within the city boundaries, it requires the highest standards of safety considerations including the seismic analysis of structure in service life.

Project Requirement

The fast track project has typical structure for its Line 1 alignment, where the viaducts are supporting 2 levels of pathways, lower one for NH-7 and upper one for the metro rail. As the impact loading is a big concern due to train movement.
Being the stretch of always busy traffic, a solution was required which does not have to revise the existing design. Plus a major concern was the impact on speed of the otherwise fast moving project. The issue was concerning to all the stakeholders especially the GC for the project, who were looking to maintain the agility as well as find a sustainable solution.

Solution

Dextra Introduced Shear Key Bars for the priority section allowing the structure to neutralize the seismic forces. This not only helped the contractor to get the work done faster, but also enabled the client to go for the trial run earlier than expected.

The Doha Metro is a rapid transportation system, designed as an integral component to the larger Qatar rail network. This country wide mega-scale infrastructural project consists of 300km of rail and 100 stations. The rail network to reduce traffic congestion, and to connect the people of Qatar with the rest of the GCC region. At the city scale, currently under construction, the metro is projected to be operational by the end of 2019. It will serve Doha and its surrounding suburbs with stations located in all major nodes of the metropolis. Doha Metro will be operating both at grade and below grade, with the majority of the metro project being underground. Complex tunneling and soil retaining solutions by Dextra were utilized in the construction of this project.

Glass Fiber Reinforced Polymers (GFRP) as Tie-back anchors to retain soil

To eliminate concerns of encroachment, and obstacle for future construction projects, the Diaphragm Wall (D-Wall) at Al Sadd C-Ring Station were post-tensioned anchored with ASTEC Active Active Anchor. These high performance, fully cut-able GFRP anchors were chosen by ALSYJ JV contractors and the D-Wall anchors of choice. This innovative solution was chosen because it can be cut by Tunnel Boring Machines (TBM) or standard excavation equipment, it also doesn’t need to be removed from the ground even in temporary applications. For Al Sadd C-Ring Station 7,113 strands for GFRP rebars were used to make approximately 700 ground retaining anchors used in the D-WALL around that station.

The Second Ho Chi Minh City Environmental Sanitation Project consists of the construction of interceptor that will convey the wastewater collected from the Nhiêu Lộc-Thị Nghè Canal and District 2 areas of Ho Chi Minh City to the treatment plant.

Dextra has been involved in the construction of the large underground system by supplying 40 Soft-Eyes to assist in the tunnel breakthroughs.

The cuttable Glass Fiber Reinforced Polymer (GFRP) Soft-Eyes were applied to reinforce 21 shafts, allowing the penetration by the Tunnel Boring Machine (TBM) without the need of removing steel reinforcement and without the risk to damage the TBM’s head.

With its completion, planned to be in 2022, the wastewater services in HCMC will have a considerably more sustainable nature, and will be remembered as the first big step toward the alleviation of the environmental and sanitation issues of the Country.

Doha Metro Phase 1 is Qatar’s mega infrastructure project of three metro lines with a total length of 164 km. The first phase involves the construction of red, green and gold lines and their major stations. It is a part of a US$36,000 million Doha Metro Rail Network Project, aiming to reduce the city’s road traffic congestion while facilitating the connection between Qatar and other Gulf countries.

The required completion period of this project is extremely short: with excavation starting in mid-2013 and operations expected by 2019. With the timeline of the project being constrained, high innovative solutions are required to complete the building of underground structures in a minimal amount of time.

Dextra’s FRP Active Anchors as temporary tie-backs in retaining walls

Composite materials have been used for over 20 years as temporary reinforcement in concrete structures. In Doha metro phase 1, both Dextra’s post-tensions carbon-FRP (CFRP) Active Anchors and glass-FRP (GFRP) Active Anchors have been used in retaining walls. When used as temporary tie-backs, CFRP material is offering the most advanced technical solution thanks to its superior properties in tensile, creep and durability, while the GFRP Anchors offers a cost-effective solution without technical compromise.

GFRP anchors can advantageously replace steel removable anchors to prevent encroachment of neighboring plots. This is why nowadays, GFRP anchors account for more than 90% of the FRP anchors installed in the region.

For the first phase of the Doha Metro Rail Network project, Dextra has been supplying 150 CFRP Active Anchors and 700 GFRP Active Anchors to date.

ASTEC Soft-Eye for a better penetration of TBMs

Dextra’s ASTEC Soft-Eyes is a unique technology using cut-able GFRP reinforcement as a replacement of conventional steel rebars. Since 1996, this solution has become a standard concept in the design of shafts and subway stations. More than 10 sets of Dextra’s ASTEC Soft-Eyes have been supplied and used in Doha Metro construction project as per May 2018.

To reduce traffic congestion on Mexico – Toluca highway, as well as to ease connections between both cities, the Secreatariat of Commuciations and Transportaion (SCT) is undergoing the construction of the new Mexico city areas’ 55.7-kilometer rail line. Aiming to be an environment-friendly project, the commuter rail line includes 4.7-kilometer double-tube tunnel in highly complex terrain and natural protected areas.

The new train will connect Toluca Valley to Mexico City, and will provide a service to an estimated 270,000 commuters. The line included 6 stations: 2 terminals (Zinacantepec and Observatorio) and 4 intermediate (Cristobal Colon, Metepec, Lerma, and Santa Fe). It will also be a backbone for Mexico City area’s regional and urban transport.

The construction being initiated in 2015, the railway is scheduled for completion in 2019.

Light and productive rebar coupler solution for the construction project

For the reinforcement of the railways concrete structures, Dextra supplied more than 100,000 Rolltec splices. The system is a practical and economic alternative to laps. Rolltec is also supported by one rebar preparation equipment, and only one man is needed to operate the machine.

Plus, thanks to the performance of our machines, the thread is ready in less than 30 seconds!
Moreover, with Rolltec system, the same type of coupler can be used for both standard and position applications, resulting in an optimized inventory of the project.

For more information about our projects in Latin America, contact our Panama Office.

Since the first 29km segment of the Metro Line 1 opened in 1987, the Cairo Metro project has revolutionized the transit system in the capital.
Currently the whole network comprises 3 operational lines numbered from 1 to 3. Line 3 consists of four phases, and the first segment started operation in 2012.

Three new metro stations were opened as part of the fourth phase of the third line on June 15, 2019, a week before the kickoff of the 2019 African Cup of Nations (AFCON) in Cairo.

Dextra has continuously provided construction solutions since the operation of Line 2 in 2000, delivering since then more than:

-1,400,000 rebar couplers

-7,000 sonic tubes

-60 soft-eyes

Bartec rebar couplers are used for rebar reinforcement of tunnel and station structures on both underground and elevated metro lines as a way to reduce steel congestion and improve tensile connection.

Moreover, the integrity test of the metro foundations using the Cross Sonic Logging (CSL) testing method was facilitated by the usage of SONITEC sonic tubes, designed for easy assembly and installation in reinforcement cages.

Dextra’s ASTEC soft-eyes are made of GFRP rebar to reinforce D-Walls in underground tunnels, which can easily be cut by Tunnel Boring Machine (TBM), resulting in time and money savings.

The project is still ongoing and the fourth line of the Cairo Metro is expected to start operation in 2020.

हो ची मिन्ह सिटी मेट्रो - लाइन 1 शहरी रेलवे प्रबंधन प्राधिकरण (एमएयूआर) द्वारा शुरू की गई मेगासिटी की 109 किलोमीटर रेल लाइन परियोजना का पहला हिस्सा है।

हासिल होने पर, जन-पारगमन प्रणाली एचसीएमसी क्षेत्रों को 6 मेट्रो लाइनों के साथ कवर करेगी, जिससे निवासियों और पर्यटकों को शहर के चारों ओर आसानी से और आसानी से आवागमन करने की सुविधा मिलेगी, जिसके परिणामस्वरूप शहरी जीवन की गुणवत्ता बेहतर होगी।

परियोजना के पहले चरण में 19.7 किलोमीटर लंबी रेलवे लाइन का निर्माण शामिल है, जो बेन थान मार्केट और सुओई टीएन पार्क को जोड़ती है। इसमें 11 स्टेशनों के साथ 17.1 किलोमीटर एलिवेटेड रेलवे और 3 स्टेशनों के साथ 2.6 किलोमीटर भूमिगत लाइन का निर्माण भी शामिल है।

वियतनाम के सबसे बड़े शहर के निर्माण के लिए, डेक्सट्रा कंक्रीट सुदृढीकरण और बार सिस्टम समाधान दोनों की आपूर्ति कर रहा है।
भारी प्रबलित क्षेत्रों में स्टील की भीड़ को कम करने के लिए, ठेकेदार शिमिज़ु-माएदा ज्वाइंट ऑपरेशन ने डेक्सट्रा के अंतिम एंकर का विकल्प चुना। हेडेड बार रीबार हुक का एक सरल विकल्प है।

इंस्टॉलेशन केवल सुदृढीकरण बार के अंत में कॉम्पैक्ट एंकर प्लेट को पेंच करके किया जाता है। समाधान अंततः प्रक्रिया को आसान बनाता है, जिसके परिणामस्वरूप बेहतर कंक्रीटिंग गुणवत्ता प्राप्त होती है।

ग्रैंड पेरिस एक्सप्रेस वर्तमान में यूरोप में विकास की सबसे बड़ी परिवहन परियोजना है।

नए 200 किलोमीटर, 68-स्टेशन स्वचालित रेलवे नेटवर्क में पेरिस के चारों ओर एक रिंग रूट (लाइन 15) और आसन्न इलाकों को जोड़ने वाली तीन अतिरिक्त लाइनें (16, 17 और 18) शामिल हैं।

ये 4 नई लाइनें राजधानी का चक्कर लगाएंगी और 3 हवाई अड्डों और कई व्यापारिक जिलों से जुड़ेंगी। यह प्रतिदिन 2 मिलियन यात्रियों को परिवहन करेगा। 2030 तक निर्धारित परियोजना के पूर्ण समापन के साथ, लाइनों को चरणों में खोलने की योजना बनाई गई है।

लाइन 15 का निर्माण 2015 में शुरू हुआ, इसका पहला खंड पोंट डी सेवर्स मेट्रो स्टेशन और नॉइज़ी - चैंप्स आरईआर ए स्टेशन के बीच था।

डेक्सट्रा उस चरण में स्टेशनों की संरचना के स्तंभों को जोड़ने के लिए 100,000 फोर्टेक रीबार कप्लर्स प्रदान करके शामिल था।

इसके अतिरिक्त, डेक्सट्रा ने सीएसएल (क्रॉस सोनिक लॉगिंग) विधि का उपयोग करके संरचनात्मक अखंडता परीक्षण की सुविधा के लिए 15,000 मीटर सोनीटेक सोनिक ट्यूबों की आपूर्ति की, इस प्रकार भविष्य के भूमिगत स्टेशनों के लिए बनाए जा रहे गहरे ढेर और डायाफ्राम दीवारों के भीतर कंक्रीट की एकरूपता सुनिश्चित की गई।

लाइन 15 का पहला खंड 2020 में खुलने वाला है।