Metro & Rail Infrastructure
Viaducts, station concourses, tunnels and cut-and-cover boxes move, leak and carry load in ways ordinary buildings never do. Dhawan Associates supplies and installs high-movement expansion joints, tunnel waterproofing, injection grouting and structural repair systems built for metro and rail service — including grouting on the Chenab Bridge for AFCONS.
Structures That Never Stand Still.
A metro viaduct expands and contracts every day with temperature, flexes under every trainset, and must survive the design earthquake without dropping its deck. A station box sits below the water table and cannot leak onto passengers or track. These are not building problems — they are movement, water and load problems, and they decide which materials belong on site.
Bridge and viaduct decks carry large thermal and live-load movement across every gap, so the joint has to accommodate travel in three axes while staying watertight and taking wheel or maintenance load without curling. Station concourses and platform slabs need durable, trafficable joint covers and floors that survive footfall, cleaning and rolling loads for decades.
Underground and cut-and-cover works add hydrostatic water pressure. Tunnel segments, construction joints and the box roof all have to be sealed against a standing water table — and when a leak does appear on a live structure, it has to be arrested by injection without shutting the line. Get the joint, the water barrier or the grout wrong here and the fix costs a service window, not just material.
What Goes Wrong On Metro & Rail Work.
The recurring failure points we are called to fix — and design out from the start.
- High-movement deck joints that were under-specified. A joint sized for a building cannot absorb bridge and viaduct thermal plus live-load travel, so it tears, extrudes or seizes and starts leaking onto the pier below.
- Water table against station boxes and tunnels. Cut-and-cover roofs, base slabs and construction joints under hydrostatic pressure seep if the membrane, waterstop or joint sealing was not detailed as a continuous system.
- Live leaks that cannot wait for a shutdown. Cracks and joints weeping on an operating structure need PU or cementitious injection that stops water while the line stays in service.
- Seismic demand at the joint. Elevated corridors need joints that survive the design earthquake movement without dropping the deck or shearing the anchors — a different class from routine thermal joints.
- Concrete distress on ageing or fast-tracked structures. Honeycombing, cover spalling and cracked piers need structural grouting, repair mortars and protective coatings before reinforcement corrodes.
One Accountable Team, Joint To Finish.
We specify, supply and install the full envelope — joints, waterproofing, grouting, flooring and coatings — from genuine authorized-channel material, so the specification and the workmanship carry one name.
Tunnel & Box Waterproofing
Membrane, crystalline and liquid systems for cut-and-cover roofs, base slabs, retaining walls and station boxes against a standing water table.
Waterproofing serviceInjection Grouting
PU and cementitious injection to arrest live leaks and structural grouting to fill voids and re-bond cracked concrete — often without a shutdown.
Injection groutingConcourse & Depot Flooring
Epoxy and PU floors for station concourses, depots and maintenance sheds that take footfall, cleaning chemicals and rolling load.
Industrial flooringProtective Coatings
Anti-carbonation and protective coatings for piers, decks and exposed concrete to slow reinforcement corrosion on exposed corridors.
Protective coatingsWaterproofing Products
Membranes, crystalline systems, integral compounds and waterstops — supplied genuine, batch-coded, with GST invoice.
Product rangeSealants & Waterstops
PU, polysulphide and hybrid sealants by movement class, plus PVC and swellable waterstops for construction joints.
Sealants rangeThe Joint Is Where Metro Structures Fail First.
On a viaduct or a station, the expansion joint is the one detail that moves every single day — and the first place water finds a way in. A joint that was sized for a building will not take the movement, the load or the seismic demand of rail infrastructure. This is the detail we manufacture for, under our own brand.
Dseal expansion joint systems are built by our group company Dseal Solutions Pvt. Ltd. for exactly these conditions: large-movement deck and viaduct joints, trafficable concourse and platform joints, and seismic systems for elevated corridors — each with an integral water barrier so the gap that has to move is also the gap that stays dry.
- Large-movement & seismic covers for viaduct decks and elevated corridors, with anchorage designed to take the load.
- Trafficable floor & wall joints for station concourses and platforms, with EPDM/TPR inserts.
- Built-in water barrier so the moving joint sheds water clear of the structure below.
Proven On Heavy Rail Infrastructure.
Our materials and crews have served demanding rail and infrastructure work, including grouting on the Chenab Bridge for AFCONS — the kind of structure where the tolerance for a leak or a failed joint is effectively zero.
On metro and rail projects that same discipline applies at every scale: specify the system to the movement and the water table, supply genuine authorized-channel material, and install it with trained crews so the specification, the material and the workmanship never point fingers at each other.
More Industries We Serve.
All Industries
Every sector we specify and install for, from infrastructure to industrial buildings.
Industries hubBridges & Highways
Deck expansion joints, bearings, structural grouting and protective coatings for road infrastructure.
Bridges & highwaysWater-Retaining Structures
Tanks, STPs and reservoirs — waterstops, crystalline waterproofing and leak-arrest injection.
Water structuresMetro & Rail FAQs.
What kind of expansion joint does a metro viaduct need?
One built for large movement and, on elevated corridors, seismic demand — with anchorage designed for the load and an integral water barrier. A building-grade joint will not take viaduct thermal and live-load travel. Our Dseal expansion joint systems are made for these conditions; see dseal.in for movement and load selection.
Can you stop a leak in a live tunnel or station without a shutdown?
Usually, yes. PU and cementitious injection grouting arrests water at cracks and joints from the accessible face, so leaks can often be sealed while the structure stays in service. Send photos on WhatsApp and we will scope it.
How do you waterproof a cut-and-cover station box below the water table?
As a continuous system — membrane or crystalline waterproofing on the box, waterstops at every construction joint, and correctly sealed movement joints — so there is no single weak point for hydrostatic pressure to exploit. See our waterproofing service and products.
Do you supply genuine, authorized-channel material for government-spec work?
Yes. We supply factory-sealed, batch-coded material from the authorized channels of Fosroc, Sika, Dr. Fixit, MC-Bauchemie and STP with GST invoice, matched to the specification your consultant or contractor is working to.
Do you both specify and install, or only supply?
Both. We run trained applicator crews for waterproofing, injection grouting, flooring and expansion joint installation, so the specification, the material and the workmanship come with one accountable name. See our services.