Dubai Municipality has constructed a stormwater system to secure a future-safe infrastructure for the residents and businesses in the Emirates.
Dubai Municipality is one of the largest governmental institutions in the United Arab Emirates. Over the years, it has assisted in making Dubai one of the most advanced and sustainable cities in the world.
In September 2017, the municipality undertook the construction of a deep tunnel storm water system that will provide the needed infrastructure to serve Dubai's growing residential and business communities.The aim of the project is to protect the area’s homes and businesses from flooding and rising groundwater in the event of rainfall.
The tunnel will tackle both rainwater and groundwater and will drain almost 40% of the entire urban area of Dubai including the flagship project Dubai South a 145 sq.km master planned smart sustainable city, home to the world largest airport in the making - Al Maktoum International Airport, the World Expo site and several other emerging developments.
The system consists of five key elements :
- A groundwater and stormwater collection network
- A 12 km long, 10m diameter and up to 70m deep tunnel
- A holding pond
- A high efficiency pumping station
- A sea outfall
The main tunnel will convey the stormwater and groundwater flows to the terminal pumping station on an island in the sea. Two large excavations will be constructed for the large pumping station and adjacent gate shaft (4 nos.) in the tunnel will connect the two excavations at depth with three piped outfalls that will extend from the terminal pumping station out into the sea. The construction of the rainwater and surface tunnel was awarded to the main contractor Besix Contracting in 2017.
Scope of work
The scope of work for AVK involved the supply, installation, testing and commissioning supervision of the largest bulk head gate ever installed in the region; 5.2M x 5.2M overall dimension of gate including the removable frame 11.5M x 6.5M in the drainage tunnel leading the water into the Arabian gulf.
After numerous consultations with Dubai Municipality, Stantec consultants and Besix Contracting the local AVK team along with Orbinox engineers arrived at a bespoke penstock solution.
A specially designed bulkhead gate penstock was engineered to meet Dubai Municipality’s challenging requirement of a large gate which is completely removable and serviceable, meaning; the door and the frame can be removed for general on-site maintenance at any time.
Finally, after several brainstorming sessions the gate with special retractable frame design, jack bolts and female anchor bolts, all of which can be removed and replaced if required, was devised.
The huge dimensions of the gate came with its own challenges too during the pandemic. The gate had to be transported in eight crates from our factory in Spain. Parts were then fabricated and assembled locally in Dubai within a week, and was finally transported back to the installation site using special transportation vehicles for the installation and commissioning process. The frame was lowered into its final location using a heavy-duty crane with pinpoint accuracy with +/- 2 millimeters. The positioning and anchoring of the gate into its final position was accomplished using specialized jack bolt system; a unique technique for this type of removable penstock. Not only was the AUMA electric actuator used for operating the penstock specially designed and manufactured for this project, the door assembly operation uses a combination of twin spindle, gearbox, and actuator; making this whole solution exceptional in every way.
The gate was successfully delivered in September 2020 as per client requirement, and installed with millimeters of precision at the worksite within remarkable time frame of two months by December 2020 under expert supervision of onsite engineer Anand Krishnamurthy and Manuel Palomeque Orbinox, Spain remotely.
The Bi-directional penstock stops water from both directions and is able to withstand a water column of 20 meters high and water pressure up to (2 bar). Manufactured in super duplex steel, it can also withstand the highly corrosive nature of the groundwater and stormwater being transported form the pumping station into the sea.
Supply, Supervision of Installation, Testing and Commissioning of 1 Nos 5.2 x 5.2 Meters Bulkhead Gate Pentsock for a 12 meters wide stormwater pit.
The main pumping station can handle 110 cubic meters of water per second, equivalent to discharging 3,800 Olympic swimming pools into the Arabian sea - every day.
The Tunnel has a length of over 10 km, which serves an area of 490 km making it the largest in the Middle East and the Arab world.