Vishwajeet Ahuja

Senior NATM Design Engineer, Louis Berger Asia, Mumbai, India
Duration: November, 2017
Project and Responsibilities:
Mumbai Metro Line 3, Mumbai, India
Part of General Consultant (the Engineer) with the following responsibilities:
a. Senior reviewer of all NATM primary support design works (seven station, more than 90 crosspassages,
two crossover caverns, two sets of stabling tunnels);
b. Interfacing with designers of the seven CJV/DDC teams for approvals of NATM primary
support;
c. Review of rock slope support system of NATM related stations (interfacing with Geotechnical
team and I&M teams);
d. Interfacing with Architectural, MEP, and TVS disciplines for General Arrangement accuracy;
and
e. Interfacing with construction supervision team for Quality and Methodology requirements for
NATM works.

Researcher (Sprayed Concrete Lining), University of Warwick, Coventry, UK
Duration: September, 2013

October, 2017
Project and Responsibilities:
Non-destructive approach for sprayed concrete lining strength monitoring
Established a strength modelling procedure for sprayed concrete lining works. Strength modelling
procedure can be applied to any type of sprayed concrete works (primary and secondary). Strength
development can be assessed since the time of spray. A real-time application only requires a
temperature measurement device (such as thermal imaging camera). The approach has a potential
to assess fallout risks. Procedure can be modified to evaluate and design sprayed concrete mixes.
Modelling procedure required developing an experimental methodology to estimate strength
development modelling input parameters. Laboratory experimentation of sprayed concrete mixes
involved isothermal calorimetry, thermogravimetry and X-Ray diffraction. Testing conducted
based on ASTM standards (C1365, C1679 and C1702). On-site experimentation involved sprayed
concrete strength testing and thermal imaging. Strength testing conducted per EN 14487 and 14488.
Experimental methodology has been verified through extensive laboratory and on-site testing of
sprayed concrete mixes pertaining to Whitechapel Station primary lining works and Bond St
Station Upgrade secondary lining.

Tunnel Engineer, ATKINS China Ltd., Hong Kong
Duration: April, 2013 August, 2013
Projects and Responsibilities:
Tunnel Design for Causeway Bay Slip Road 8 Mined Tunnel
Evaluated 45 m long soft ground mined tunnel option under an active highway with an overburden
varying between 4 and 8 m. Two different type of cross-sections were evaluated – Box (20m x
13m) and Modified horseshoe (18m x 15m) shaped tunnel sections. Support systems included presupport
using microtunnelled steel pipes (1600mm OD), steel ribs, sprayed concrete primary lining
(400 mm thick), and cast in-situ final lining (1000 mm thick). Excavation sequence optimisation
and ground settlement assessments made using empirical approach and 2D FE modelling in Plaxis.
Structural analysis (using SAP2000) and design based on British and HK standards including BS
8110, Codes of Practice for Concrete (2004) and Steel (2005), and Geoguides 6 and 7.
Hong Kong Link Road Tunnel SHT Tunnel – Cross passages
Performed structural analysis and design of permanent lining (550 mm thick), plinths, and collar
(600 800 mm thick) for horseshoe shaped cross-passages (3.6 m x 3.6 m). Multiple loading cases
analysed using SAP2000 to meet Code of Practice for Concrete (2004) requirements.
Nam Fung Tunnel and Ventilation Buildings

Rock tunnel temporary support

~ 7m, A ~ 31m2). Deep excavation made in hard rock and supported using rock dowels and sprayed
concrete. Comment response required reviewing of existing design made using empirical approach,
Unwedge, Rocsupport, and Phase2.
Independent review for Tintenbar to Ewingsdale

Pacific Highway Upgrade tunnels
Performed structural checks for permanent lining of modified horseshoe shaped cross-passages (L
~ 27m, A ~ 34m2) in hard rock using Australian standards (such as AS 3600, AS 4678, and AS
5100) as well as Eurocode 2.

Tunnel Design Engineer, SMEC India Pvt. Ltd., Gurgaon, India
Duration: September, 2011

March, 2013
Projects and Responsibilities:
Detailed design of Rohtang Tunnel, Manali, India
8.8 km long NATM tunnel (excavation sections of up to 14 m widths at springline level) with
overburden of up to 1900m. Other excavations included lay-by niches and equipment storage
cavern.
Responsible of detailed design of excavation and support measures. Primary lining support
designed for ground conditions varying from hard rock to weak ground conditions (categorised into
seven classes). Support systems included rockbolts, fibre reinforced sprayed concrete
(complemented with wire-mesh and lattice girders). Classified an additional support category for
flowing ground conditions for fractured and crushed rock with high water ingress. Specified
stringent face-support and drainage measures and supplemented primary support with pipe-arch
canopy.
Designed permanent concrete works for cast in-situ concrete lining, walkways, escape route box
culvert and ventilation slab. Other aspects included tunnel drainage arrangements using strip
drainage and waterproofing membrane. Miscellaneous activities included incorporating design
changes based on as-built information, such tunnel realignment, and earthworks at portal.
Responsible for design management in terms of delivering detailed design drawing by coordinating
with Client (Border Roads Organisation, India), Contractor, Independent Engineer, and Design
checker.
Represented SMEC and facilitated the Client for collecting E&M bids for evaluation purposes.
Pre-bid support for construction of highway scheme for Z-Morh tunnel, Kashmir, India
Provided design support to contractor, as part of technical team, for civil works of 6.5 km long 10m
wide two-way tunnel with 3.5m wide parallel egress tunnel in Himalayan geology (mainly hard
rock).
Business Development / Opportunity Management
Proposal Preparation (Technical / Risk Assessment / Financial) for multiple projects

Tunnel/Civil Engineer, Gall Zeidler Consultants, Ashburn, VA, USA
Duration: January, 2008 December, 2010
Summary: Numerical analysis for multiple projects using Abaqus and Phase2
On-site Engineering Support for Tunnel Construction
Construction & Design Document development like drawings, specifications,
work plans, etc.
Projects and Responsibilities:
Twin NATM Tunnels for Dulles Corridor Metro Project in Fairfax County, VA

Design- Build Project
Performed 3D FE analysis for Soft Ground (residual soils) using Abaqus for 520m long 6m high
and 6m wide NATM tunnel under shallow overburden of 4m. Required geotechnical interpretation
of ground. Highlight was about 3D modelling of complex dome shaped heading face under pipearch
canopy. Model predicted surface settlements matched the monitored data.
Provided on-site engineering support such as development of Calculations, Drawings (detailed
design, construction and as-built), Method statements and Work Plans, etc. Responsible for
document approvals and submittals.
Designed reinforced cast in-situ final lining including base slab (calculations and drawings).
Responsible for contacting suppliers, collecting quotations and recommending supplier for final
lining reinforcement meshes bent to lining curvature.
Twin NATM Tunnels for CALTRANS at Devil’s Slide, California
Performed 2D FE analysis for weak and fractured rock using Phase2. Multiple sections analysed
for different overburden and ground types for 2.2km long, 10m high, and 11m wide NATM tunnels.
Responsible for geotechnical interpretation and report preparation.
Zone 2 and Zone 4 Pipe Box Tunnels for Sentosa Gateway Project for LTA, Singapore
Responsible for development of tender drawings and specifications for two Pipe Box Tunnels in
soft ground with shallow overburden of less than 3 m. 95m long two lane and 117m single lane.
Developed Approach in Principle (AIP) for construction of 14m x 9m and 11m x 8m tunnel sections
provisioned beam frames for pipe-box support and cast in-situ reinforced concrete box.
Lift Shaft Excavation for Step Free Access Upgrade for Green Park Station, London
Performed for 2D / Axisymmetric (undrained), and 3D (drained) FE analysis using Phase2 and
Abaqus for NATM based 28m deep and 9 m dia oval shaft. Additionally 13m high and 9m high
stub at shaft bottom. Required modelling of complex set up of existing structures (escalator barrel
with plinths, ticket box, platform tunnels and cross-passage) in London Clay material
Pre-Bid review of SEM Tunnels in Northern Line at SPADINA Subway Extension, Toronto
Mentored graduate engineer for 2D FE analysis using Phase2 for 220m long, 21m wide and 8m
high three track SEM tunnel with shallow overburden in Lower Till (Soft Ground)

Design Intern, Dr. Sauer Corporation, Washington DC Office (Herndon, VA)
Duration: May

August, 2007
Project and Responsibilities:
ELS works for Early Access Chamber (Slurry wall) Queens Open-cut Excavation, East Side
Access
Performed structural analysis and design of six levels of bracing structure of trapezoidal slurry wall
chamber (L~38m, W~17m, D~25m). Bracing structure involved use of built-up strut (pipes &
channels) and waler (double beam) sections. Provisions included cross bracing, knee bracing as
well as underpinning using rock anchors. Structural analysis performed made using ENERCALC,
v5.8 and members designed to conform to AISC 360. All weld connections designed to conform
to AWS D1. Analysis included slurry wall and soldier pile capacity check. Project involved direct
communication with contractor. Prepared calculation report and coordinated with draftsman for
drawings preparation.