Monitoring System of Rigid & Flexible Barrier at Hillsides – Civil Engineering and Development Department (CEDD)
Client: Civil Engineering and Development Department (CEDD)

Scope of works:

Rockfall and Debris Flow Barriers are protection systems that are designed to retain falling rocks or water born debris by dissipating their energies throughout the system. The systems are usually constructed with steel posts that support a flexible barrier comprised of a series of steel cables and steel mesh or ring nets.

There are two flexible barrier system that were constructed under the Contract No. GE/2011/07 and GE/2011/15 under the Landslip Prevention and Mitigation Programme of the Civil Engineering and Development.

FT Laboratories Ltd. specialises in monitoring and has been in charge of the design and provision of remote monitoring systems to monitor the occurrence of debris flow and the responses of the flexible barrier system under action.

The proposed flexible barrier monitoring systems are configured from the full integration of a sensory system, a data acquisition system, power supply units and associated equipment.
The sensory system consists of 3 groups of instrumentation, namely,

     Þ sensors for event alarming and monitoring system triggering at the commence of debris flow or land slide;

     Þ sensors for measuring structural response and integrity of the flexible barrier;

     Þ sensors for logging the events of debris flow or land slide for record and debris flow front analysis.

The remote connection and data transfer back to CEDD’s office is facilitated by a 3.5G wireless network. The 3.5G wireless network is established by the 3.5G modem connected in the 3.5G router and the computer in the control cabinet located on site.
Tripwire Switches
Conceptual design of a remote monitoring system for flexible barriers

For further enquiries, please contact:
Mr. Eric Ho
Tel: +852 2758 4861

Mr. LAI Wing Chun
Tel: +852 2758 4861
The proposed flexible barrier monitoring system operates in three modes:

Þ stand-by mode (before triggering)
Þ landslide-based active mode (automatic triggered) and
Þ rainfall-based active mode (user triggered)
HD Camera with Infrared Flood Light
Ultrasonic Sensor
Tension Link Sensor
Software Features: Displays live signals for real-time visual analysis; analyzes data or save it to disk for later analysis; converts signals automatically to engineering units to support a variety of data acquisition applications from temperature measurement to high speed testing and analysis.