
- Geotextile materials
- - Warp-Knitting Polyester Geogrid
- - Fiberglass Geogrid
- - Bidirectional Stretch Geogrid
- - Unidirectional Stretch Geogrid
- - Steel-Plastic Geogrid
- - Polypropylene Geogrid
- - Geomembrane
- - Composite Waterproof Roll
- - Short Fiber Needle-punch Geotextile
- - Polyester filament geotextile
- - Bentonite Waterproof Blanket
- - Geocell, High-strength Geocell
- - Rubber Water-stop Strip
- - Water Swelling Strip
- - Three-dimensional Composite Drainage Network
- Plastic pipe
- - Steel-plastic flexible permeable hose
- - Plastic Blind Drain
- - Double-wall Corrugated Pipe
- - Grouting Pipe (Splitting grouting pipe)
- - Inclinometer tube
- - Inclinometer
- - PVC Water Level Tube
- - Steel Ruler Level Gauge
- - PVC subsidence pipe
- - Layered subsidence magnetic ring
- - KY type steel ruler subsidence gauge
- - Bentonite mud ball
- Monitoring instruments
- - Vibrating wire reinforcement tensiometer
- - Vibrating Wire Type Soil Pressure Gauge
- - Vibrating Wire Pore Pressure Gauge
- - Vibrating Wire Type Anchorage Dynamometer
- - Vibrating Wire Counterforce Dynamometer
- - Surface Strain Gauge
- - Vibrating Wire Type Strain Gauge
- - Steel wire type displacement meter
- - Steel Wire Type Multiple Point Displacement Meter
- - Tunnel Convergence Gauge
- - Portable Frequency Readout Instrument


The tunnel convergence gauge (also known as convergence gauge) is a kind of engineering test instrument for measuring and monitoring of deformation of the tunnels and underground caverns. This displacement meter uses one regular steel ruler under tension by one heavy hammer to transfer the displacement; a dial indicator is used for reading of the relative position change of certain two points in the tunnel and hence to calculate the relative displacement of two points in the connection direction (namely convergence value); the measuring of the peripheral displacement can find the rule for deformation of the surrounding rocks and provide necessary information for the design and construction of support system and provide means for ensuring safety of the construction as well.
Tunnel Convergence Gauge