Ground
Curtain and consolidation grouting
A grout curtain is a continuous treated wall in the ground that cuts a seepage path. Consolidation grouting binds jointed rock or loose ground over an area, so it carries load and lets less water through. We design and carry out both, with the grout chosen for the water we find.
When to call us
The signs
- Seepage and uplift under dams, barrages and spillways.
- Water arriving from a known direction: a river, a reservoir, the sea or a hillside.
- Jointed or weathered rock under foundations.
- Soil under heritage and other structures that are settling.
- 1Note 1: Reservoir: water under head on the upstream side.
- 2Note 2: Grout curtain: deep holes below the heel, grouted in stages, with the spacing closed until the take falls.
- 3Note 3: Consolidation grouting: shallow holes under the base bind the jointed rock.
- 4Note 4: Drainage gallery and drain holes relieve water pressure behind the curtain.
- 5Note 5: The seepage path under the dam is cut off, and uplift under the base falls.
- 6Note 6: Water pressure (Lugeon) tests in the holes before and after grouting.
How we do it
Method, step by step
Investigate
Geology, water pressure (Lugeon) tests and the direction of flow.
Design
Line, depth and spacing of the holes; stages; grout mixes; acceptance values.
Grout in stages
Primary holes first, then secondary and tertiary holes, closing the spacing until the take falls.
Match the grout to the flow
Cement or microfine cement in open rock; water-reactive PU or silicate resin where water is flowing or the fissures are fine.
Test
Water pressure tests in check holes, before and after, against the agreed acceptance value.
What we use
Made at our plant in Alwar
GeoFine (aqueonglobal.com, opens in a new tab)
Rock and soil injection where a cementitious grout is specified.
DrucHyd 2C (aqueonglobal.com, opens in a new tab)
Curtain grouting against active inflow; waterproofing and consolidation under water pressure.
DrucPietra (aqueonglobal.com, opens in a new tab)
Low-foaming resin for deep curtain grouting and rock consolidation.
DrucStone (aqueonglobal.com, opens in a new tab)
Structural anchoring and consolidation.
Quality
Checks and proof
- Lugeon tests before grouting, and in check holes after it.
- Take per stage plotted against the closing hole spacing.
- Acceptance value agreed with the client before work starts.
On record
Where we have done it
T-46 P2, Sangaldan, USBRL
Ballastless track that settled further every monsoon, lifted back to its design profile on a live line, with the ground beneath made stable.
Badi Patan Devi heritage site, Patna Sahib
Soil under a heritage site consolidated by chemical grouting and self-drilling anchors, with the strength gain measured by IIT Patna.
Micro-tunnel pit, Pipavav
Seawater pouring into a micro-tunnel pit through a crack, after repeated attempts to seal it had failed. Sealed up to 85 per cent by grouting.
Questions
What clients ask
What does a Lugeon value mean?
It is the rate at which rock takes water under pressure in a test section of a borehole. It is the usual way to measure how open the rock is before grouting, and how tight it is after.
Can a curtain be grouted with resin instead of cement?
Yes, where the water is flowing or the fissures are too fine for cement. Water-reactive PU sets in the presence of water instead of being washed out. On T-46 P2 a grout curtain with self-drilling anchors cut off the water coming from the hill side.
Related services
Often used together
Permeation and chemical grouting
Weak, loose or wet ground strengthened and sealed by resins and gels that fill it without moving it.
TAM grouting
Staged grouting through sleeve pipes for shafts, foundations and deep excavations.
Rock bolting and self-drilling anchors
Rock bolts, self-drilling and prestressed anchors for tunnels, portals, slopes and caverns.
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