Turkish construction company Eferay Yapi Ticaret AS and Canadian-Chinese TBM manufacturer Lovsuns Tunneling Canada Ltd, celebrated breakthrough of a 3.91m diameter EPBM wasterwater tunnel drive in Istanbul and another important step towards a cleaner environment for the rapidly expanding metropolis.
Turkey is one of the fastest growing markets for wastewater solutions, accor¬ding European Union reports. The Turkish Wastewater Treatment Ac¬tion Plan 2023 programmes an increase in the number of treatment plants from 650 in 2015 to more than 2150 in 2023. The Istanbul region, with more than 16 million people, continues to be particularly needy of wastewater management solutions.
The 3.91m Lovsuns/LNSS EPBM is part of this visionary plan and finished the first 2km long Ayvali-2 bypass tunnel in Zeytinburnu. The project will increase wastewater drainage capacity and carry the wastewater from the Bagcilar, Esenler, Gungoren and Zeytinburnu hubs of Istanbul to the Yeni Water Treatment Facility.
The TBM was launched in a 21m deep shaft and broke through into the 12m deep reception shaft after nine months of boring. Boring time should have been shorter, but problems with muck transporta¬tion during the winter resulted in a longer than expected progress.
The TBM was one of the first TBM delivery contracts for Lovsuns, formerly the Lovat company and inow an overseas subsidiary of Liaoning Censcience Industry Co Ltd, LNSS, of China based in Toronto. The machine was de¬signed by experienced ex-Lovat engineers and was manufactured in the modern Chinese facilities of LNSS.
After one month of assembly, the machine started boring in mid-December 2015 on an alignment through sandstone, siltstone, clay and soil and with the partial for groundwater content. During the last 150m of the drive, grouting injection was used to stabilize the ground and help prevent higher water ingress and secure stability of the buildings on the surface.
Due to these measures, advance of the tun¬nel was positive, achieving a best daily progress rate of 31.2m and a best week of 153m. The best monthly advance occurred in April 2016 with 512m. The alignment overburden was 8m to 40m deep with the last 150m before the reception shaft, passing only 6m beneath the foundations of nearby housing areas.
Following the first breakthrough, the TBM will be reassembled in the launch shaft in Ayazaga to complete a second drive of 7.29km between the existing wastewater tunnels of Kemerburgaz and Ambarli. For this drive the TBM will work through sandstone.
Lovsuns emerges from the Lovat company after it was sold to Caterpillar in 2008. The order of the 3.9m diameter EPBM for the two wastewater tunnels in Istanbul, was confirmed one month after Caterpillar sold the tunnelling as¬sets to the Chinese Liaoning Censcience Industry Co Ltd in November 2014. "We designed and engineered the tailormade TBM for Istanbul in Toronto and produced it completely in the facility in Liaoyang China,” explained Hongyu Xue, Managing Director of Lovsuns Tunneling Canada Ltd. “In doing so, we very successfully united the best practice, knowledge and technology of both companies for the highest advantage of our customer."