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Home / Construction Plan for Geotextile Tubes in Channel Maintenance and Dredging Projects (with Silt Curta
Project Background And Objectives
The primary task of channel maintenance and dredging projects is to remove siltation and maintain navigability and design depth. Geotextile tubes (Geo-tubes) can be used to dispose of dredged materials efficiently, reduce the burden on disposal sites and form revetments or dikes. Meanwhile, deploying silt curtains during construction effectively controls suspended sediment dispersion, minimizing impacts on the surrounding ecosystem and navigation safety.
Construction Conditions
Natural Conditions:
Water depth 5–15m, current speed 0.5–1.5 knots, tidal influence significant.
Construction Environment:
Near aquaculture zones, ecological reserves and port waters.
Construction Requirements:
Maintain navigability and vessel passage during construction.
Deployment And Preparations
Overall Deployment:
A large mud receiving area is formed by using geotextile tube bag cofferdam near the construction area. The mud and sand are transported to the mud receiving area through pipelines for centralized sedimentation treatment to ensure that the mud and sand do not overflow during the construction process and reduce pollution to the surrounding waters.
Silt Curtain Deployment:
Fully enclosed silt curtains are installed around the dredging vessel operating area, sensitive areas of the waterway and drain outlets of the mud receiving area.
Equipment:
Dredgers, sand/slurry pumps, floating pipelines, cranes, survey boats, silt curtain vessels.Personnel:
Project manager, technical engineers, safety officers, crew, environmental monitors.
Construction Procedure
STEP 01
Surveying And Layout：
Use GPS and depth sounder to measure the waterway and determine the dredging range and mud receiving area.STEP 02
Foundation Preparation：
Clean the mud receiving area and lay the foundation for the pipe bags and lay a sand or gravel cushion layer if necessary.STEP 03
Silt Curtain Deployment：
Silt curtains are laid around the dredging vessel operating area, in sensitive areas of the waterway and at the drain outlets of the mud receiving area. They are anchored and fixed, and the curtains are sunk to 1.0-4.0 meters from the water surface.STEP 04
Dredging And Filling：
The dredging vessel transports the silt to the silt receiving area through a slurry pump.STEP 05
Tube Stacking：
Stack tubes in layers with staggered joints 1.0-2.0m to form revetments or dikes.
STEP 06
Maintenance And Inspection：
Regular inspection of tube stability and curtain integrity; repair promptly if damaged.
Quality Control
- Filling Control: The filling height of a single layer of geotube bags is 0.5-0.8m and allowance for settlement is reserved.
- Curtain Requirements: Two anti-fouling curtains are installed at the sluice outlets in the mud receiving area. One anti-fouling curtain is installed around the dredging vessel operation area and in sensitive areas of the waterway. Carry out daily inspections to ensure that there are no holes in the anti-pollution curtain.
- Water Monitoring: During the construction period, the suspended solids concentration at the outlet will be tested daily to ensure that the ecological impact on the waterway is controllable.
Safety And Environmental Protection
- Navigation Safety: Install buoys and guard vessels to maintain safe distances.
- Construction Safety: Workers must wear life jackets and protective gear.
- Environmental Measures: No oil or waste discharge; avoid construction during fish spawning season.
Geotextile Tubes: Structural Safety & Durability Challenges
Pain Point 01
Rapid Material Aging Shortens Project Lifespan
Customer Concern:
Traditional geotextile tubes degrade quickly under UV exposure and seawater erosion, leading to strength loss, cracks and breakage within a year. This results in sand leakage, embankment failure and high repair costs.
Solution:
Use UV-resistant high-strength geotextile tubes (tensile strength 35–250 KN/m, elongation >23%). With special treatment, the tubes can withstand natural exposure for 3 years in any marine environment, reducing embankment repair costs from the source.
Pain Point 02
Weak Seam Strength Causes Tube Rupture
Customer Concern:
Conventional tubes are stitched with portable sewing machines, with seam strength ≤30% of base fabric. When filled with sand, seawater pressure often tears the seams, especially in ports with large tidal differences.
Solution:
Adopt industrial four-line parallel stitching, ensuring seam strength ≥70% of base fabric. With trapezoidal staggered stacking, overall shear resistance improves by 40%, preventing chain reactions from local damage.Silt Curtains: Environmental Compliance & Efficiency Challenges
Pain Point 01
Poor Design Leads To Low Pollution Control, Risk Of Penalties
Customer Concern:
Conventional silt curtains use mixed fabrics sewn together, with overall strength <50% of base material. They fail under wave impact, leading to breakage, excessive turbidity, fishery disputes, fines, and suspension risks. Sediment interception is often <60%.
Solution:
Useing high-strength permeable fabric in an integrated structure. Curtain strength = 100% of base fabric. With sandbag ballast (non-corrosive), sediment interception reaches >90%, while dissipating wave energy and ensuring compliance (permeability coefficient 1.5×10⁻³ m/s).Pain Point 02
Poor Durability, Frequent Replacements
Customer Concern:
Standard silt curtains lack UV resistance and seawater durability, lasting less than 1 year. This requires annual replacement, raising offshore operation costs and delaying schedules.
Solution:
Use anti-aging integrated silt curtains, durable for 3 years in seawater, cutting life-cycle cost by 50%.Constructing new marine settlements
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