Innovative solutions for complex geotechnical and tunnelling

projects

Dr Mazin Alhamrany, BSc MSc PhD MISSMGE CEng MICE

April 2017

Summary Dr Mazin Alhamrany has experience of more than 25 years in the field of

Geotechnical and Tunnelling Engineering. Dr Mazin is specialist in the field of applications of Finite Element Method for tackling soil-structure interaction problems. He is a highly experienced in 2D and 3D Finite Element Modelling, using advanced soil models, to simulate construction staging and soil-structure interaction to produce buildable economic designs and to assess the impact of carrying out engineering activities such as deep excavations on existing adjacent structures. We have a

solid reputation in finding innovative solutions for complex geotechnical and tunnelling projects. We are proud of leading design teams for major challenging projects in The UK, Europe and Middle East. Dr Mazin Alhamrany was previously working as a Technical Director at Hyder Consulting Middle East Ltd (ARCADIS, 2012-2015), leading the Tunnels and Geotechnics Team of Dubai Office. He led the Regional Teams for the design of challenging projects such as Mega Reservoirs in Doha, Doha Metro, Doha Expressway, The Inner Doha Re-sewerage Implementation Strategy (IDRIS), Riyadh Metro, Strategic Tunnel Enhancement Programme (STEP) in Abu Dhabi and Etihad Rail (UAE). Prior to joining Hyder Consulting, He was working as Associate Technical

Director leading geotechnical team at Scott Wilson Ltd / URS (AECOM, 2005-2012) for the design of major projects in UK such as the Upgrading of Tottenham Court Road Station, Gerrard’s Cross re-design, Thames Link Borough Viaduct, Blackfriars Bridge, East London Line (Dalston station) and the Crossrail Project (Farringdon Station and Pudding Mill Lane Portal). In addition, he was responsible for developing the Numerical Modelling Team for Scott Wilson. Prior to that, Dr Alhamrany was a key member for the design of challenging projects in Europe / Holland, such as the High Speed Line Project between Amsterdam and Paris and the North-South Metro Line underneath Amsterdam Central Station Building. Dr Alhamrany has undertaken teaching, for both undergraduates and

postgraduates, in the field of Soil Mechanics and Foundation Design as well as researches adopting advanced numerical methods for solving geotechnical problems and has published several papers on these topics. For more details see our website: www.ur-geotech.com https://nl.linkedin.com/in/mazinalhamrany

Qualifications

Dr Mazin Alhamrany, BSc MSc PhD MISSMGE CEng MICE

1983 – 1986 •Ph.D. Civil Engineering; Soil Mechanics •Dept. of Civil and Structural Engineering •University of Sheffield, England

1979 – 1980 •M.Sc. Civil Engineering; Soil Mechanics •Dept. of Civil Engineering •University of Baghdad, Iraq 1968 – 1972 •B.Sc. Civil Engineering •College of Engineering •University of Basra, Iraq

Experience

A) United Kingdom

Crossrail Project (Farringdon Station) Farringdon Station is one of the major central stations to be built and involves the construction of two 400m long platform tunnels and associated cross passages with a ticket hall at either end. The West

Ticket Hall (WTH), which will house both Thameslink and Crossrail Services, includes a Circular Shaft of 15m diameter, a Rectangular Shaft of 24m by 28m, an Escalator Shaft 9m x 25m and individual 1.2m and 2.1m diameter piles to support the ticket hall and over-site development. The East Ticket Hall (ETH) includes a Trapezoidal Shaft of approximately 32m by 28m and a further Double Basement with individual 1.2m diameter piles supporting the ticket hall and another over-site development as well as works that link with London Underground Barbican Station. The excavation depth of these shafts is 25 to 30m. The works include the challenge of installing the 2.1m diameter piles of the oversite development at the WTH among the tight constraints set by the new tunnels. The piles have also been designed to carry the negative skin friction and the bending moments induced from the construction of

the future Crossrail tunnels and the adjacent Shafts. The impact of constructing deep shafts on existing buildings in the surrounding area, using 2D and 3D finite element models, has been thoroughly investigated. Design of Diaphragm walls, secant pile walls and deep excavations is part of the works. Our experience can be summarised in leading geotechnical design teams defining the most appropriate approach of analyses, liaise with wider project team, define the technical aspects that need to be checked, ensure delivering optimum design in terms of quality, costs and constructability, assessing impact of construction on adjacent structures and services, ensure having the required resources to get job done on time within the budget.

Tottenham Court Road Station Upgrade / Category 3 Check Leading geotechnical team for carrying out Independent Design Check involved carrying out 2D and 3D finite element analyses for the design of

the Double Basement, Escalator shaft and Falconberg Shaft as well as assessing impact of the construction on the existing tunnels and London Underground assets. A key challenge of this project was the need to limit deflections in the secant pile walls in order to avoid damage on the adjacent buildings and roads.

East London Line (Dalston Junction) Leading geotechnical team carrying out foundation design for Dalston, Hoxton and Shoreditch Stations of the East London Line. The work

included, in addition to the pile foundation of Dalston Station, assessing impact of constructing Dalston foundation on existing listed buildings as well as impact of Dalston station as a whole on the proposed future Crossrail tunnel. Piled-raft foundation has been designed so that differential settlement between this part and the rest parts of the station maintained with the tolerable limit. The design involved two rows of bored piles on each side of the tunnel, topped with pile caps that support walls carrying the podium slab, the station concourse and the multi-storey development above. This solution was adopted by the client after being reviewed and supported by an independent well-established geotechnical consultancy firm.

Blackfriars Bridge 407 Leading geotechnical team for carrying out Independent Design Check for assessing impact of the construction of a new concrete box structure

on the existing South Abutment of Blackfriars Bridge using 3D Finite Element Model. The problem under consideration is quite complex involving a piled raft foundation for the proposed structure as part of the structure will be founded on the existing abutment of the bridge.

Gerrard’s Cross Geotechnical Team leader for the independent checking for the design of the anchored contiguous piles walls to be installed on both sides of the existing tunnel. Advanced modelling was required to assess the stability of the anchored contiguous piles, their deflections as well as the bending moments and the shear forces.

Thames Link Borough Viaduct Responsible for assessing impact of the construction of the Borough Viaduct on the existing Northern and Jubilee lines tunnels. The work included also impact moving loads on existing buried services and LUL assets.

B) Holland

High Speed Line between Amsterdam-Paris, Holland This was one of the largest European rail projects of recent times. This project provided the Dutch with a 300-kph railway from Amsterdam southward to the Belgian border, a distance of 125km at total cost of around 6.7billion Euros. The strict requirements for this project regarding the maximum allowable long term settlement including secondary compression, considering the highly compressible organic soil

of the Netherlands, made the design process of this project a real challenge. Key member of the engineering design team for this large European rail projects of recent times. Assigned to lead the geotechnical design team for all aspects of project, including tunnelling (Rotterdam Tunnel), deep excavations and retaining structures using 2D and 3D Finite Element Modelling.

Metro Line Amsterdam, Holland Responsible for the design work including the metro line underneath Amsterdam Central Station Building. Beneath the Amsterdam Central

Station an excavation was created for the proposed tunnel. The excavation width is 18m to a depth of 23m along the whole longitudinal section of the Station. The design concept was characterised by the need to apply an innovative technology in the form of the so-called ‘sandwich wall’. This is a composite wall consisting of two rows of steel piles with a body of jet grout columns in between. This wall needed to act both as an excavation retaining wall and also as a vertical bearing wall. The installation of the wall, within certain specific conditions (limited height, sensitive historical building, and train station in service), within the design requirements set in terms of construction tolerance and water and soil retention, may be regarded as being a pioneering achievement. Responsible for leading the design team for this challenging project. This included Finite Element Analysis to predict settlements, deformations

and stresses in the sandwich walls in order to demonstrate that the proposed works would not damage the historic Amsterdam Central Station Building.

Vertical force

Horizontal force

Dikes improvement This project involves taking every necessary measures to improve and reinforce the existing embankments as well to design new dikes along

Waal and Maas rivers. The rate of construction is specified so that reasonable safety factors for stability are ensured. The build-up pore water pressures during construction and also the time required for the dissipation of the excess pore water pressures are calculated. In many sites and due to the limited time available for construction, geotextiles and/or soil improvements are applied in order to improve the shear strength against sliding.

C) Middle East Bahrain

Muharraq Geotechnical Technical Manager responsible for the design and build project for Muharraq STP and Flow Conveyance project which comprises construction of a new Deep Gravity Sewer (DGS), 97 shafts and Waste

Water Connection Network (WWCN) extending approximately 16km in length and will collect flows from the island of Muharraq and future developments on new land reclamation projects off the East Coast of the Kingdom of Bahrain.

Iraq

A project of 13 berths in Umm Qasr, South of Iraq The study was focused on, (i) if there is a need to use sand-drains in order to accelerate the rate of consolidation and so to reduce the time required for consolidation settlement, (ii) if there is a need for soil improvement in order to improve the allowable bearing capacity and (iii) How long should the preloading be applied in order to eliminate all the primary consolidation settlement, expected under the proposed permanent loading, plus such amount of secondary compression in order to reduce a post-construction settlement to tolerable values.

Babylon project, Iraq The study involved predicting the behaviour of three (30 meter high earth fill) “mountains” in Babylon ancient city. Two main aspects were thoroughly investigated; the stability and the settlement. In addition to

these two aspects, the influence of such constructions on the adjacent ruins was also assessed. Due to the importance of the ruins, suggestions were given to install inclinometers to monitor the lateral displacements during construction. It is worth mentioning that the reading-records were very close to the predicted values which have been calculated by using a computer program based on finite element method.

Kingdom of Saudi Arabia

Riyadh Metro

Riyadh Metro project, a six-line driverless network which will eventually encompass 177km and 96 stations in the Saudi capital.

Responsible for leading design team for the geotechnical and tunnel design of the tunnel and the stations, which have been subdivided into Shallow, Deep and Transfer Stations.

Qatar

Doha Metro Geotechnical design team leader responsible for carrying out geotechnical services for the two packages form the core of the Doha Metro in the old part of the city. The Red Line South runs from the Musheireb development south along Al Matar Road to E-Ring Road and the golden line starts at Airport City North Station, a double width station runs west to the Musheireb development; on the other side of Musheireb Station

Abu Hamour Abu Hamour Surface and Ground Water Drainage Tunnel, Doha – Geotechnical Director for tender design of a stormed water tunnel and associated access shafts. TBM segmental lining (main tunnel) and pipe jacking with micro-tunnelling (connection tunnels) comprise the tunnel works along the route of the drainage system. Work included feasibility studies and advance numerical analysis (Strand7) of main tunnel – shaft junctions. Also responsible for the technical design reports and tender drawings.

United Arab Emirates

Etihad Railway

Etihad Rail’s 1,200 km network will extend across the United Arab Emirates, from the border of Saudi Arabia to the border of Oman. The network will run from Ghweifat to Abu Dhabi, Dubai and the Northern Emirates with major connecting points in between, including Al Ain and Madinat Zayed. Etihad Rail will have an extensive national network with freight terminals, distribution centres and depots located close to major transport hubs, warehouses, and storage facilities across the UAE, including Mussafah, Khalifa Port, Jebel Ali Free Zone, Port of Fujairah and Saqr Port. The Etihad Rail network will also connect with the GCC network and this – once fully established – will cover the five GCC countries of The Kingdom of Bahrain, The State of Kuwait, Oman, Qatar, The Kingdom of Saudi Arabia and UAE.

Responsible for leading design team for the geotechnical works associated with this project.