Long-Term Structural Monitoring Systems

BDI Structural Monitoring System (BDI-SMS)

Bridge Diagnostics, Inc. supplies and helps install pre-configured Health Monitoring Systems for tracking long-term performance of civil structures. Since our background is in quantifying bridge responses, BDI can also help develop the optimal instrumentation plan to keep the system as simple and as robust as possible. We have found that it is usually better to use a limited number of sensors rather than collect too much data that can create a burden on the owner. Most of our sensors rely on extremely reliable Vibrating Wire (VW) technology and are ideal for monitoring parameters like pier rotations and shear crack movement in concrete structures.

Alarm Features

If sensors read outside the user set limits, the logger can send a warning to the engineer via cellular modem!

Highlights

• For Bridges and Buildings: Ideal for monitoring structural movement over the long-term such as: motion of bridge piers or building walls, the status of cracks in concrete and masonry, and strain levels induced during construction.
• Very Flexible: Data can be recorded manually or automatically. The BDI-SMS can be configured by the user to record data for a few days, weeks, months, or years.
• Low Cost and Low Maintenance: All hardware is very rugged and has been field-proven to be reliable, even in harsh conditions.
• Sensors are Entirely Re-Usable: They can be attached with adhesive for short-term testing or permanently mounted with anchor bolts or welding for longer-term investigations.
• Excellent Stability: The sensors are based on vibrating-wire technology, proven to be among the most stable for long-term measurements. The system can also record temperature, humidity, wind speed and direction.
• Stand-Alone Capability: For locations without power or phone lines available, the BDI-SMS can use its own cellular phone for communications and solar panels for power.

Specifications

Data Logging Hardware	Typically CSI CR-100 and AM16/32’s
Maximum Number of Channels:	96 Vibrating-Wire Sensors, each with internal temp sensor.
Maximum Scan Rate:	Approximately 1 sample/sec. per sensor (sequential sampling).
Power Requirement:	12VDC, use AC adapter, 12V marine battery, or solar panel.
Housing:	16in x 18in (40cm x 46cm) weatherproof fiberglass enclosure.
Lightning Protection:	Heavy copper grounding with transient and surge protectors.
Sensors	All Vibrating-Wire sensors manufactured by Geokon, Inc.
Lead Wire Length per Sensor:	Up to 6000 ft. (1,800 m).
VW Strain Gage, Surface Mount:	6 in (16 cm) gage length, 1€ resolution, longer lengths available.
VW Strain Gage, Concrete Embedment:	6 in or 10 in (16 cm or 26 cm) gage length, 1€ resolution.
VW Crack Meter (Displacement Gage):	12 in (30cm) length, ±1/4", ±1/2", ±1" (±6mm, ±13mm, ±25mm) ranges.
VW Tiltmeter:	Range: ±10°, Resolution: 10 arc-seconds (Other ranges/res. available).
Temperature & Humidity Sensor:	-30° F to 120° F (-35°C to +50°C), includes radiation shield.
Wind Speed & Direction Sensor:	0 to 130 mph (60m/sec), 360°, mounts to 1" pipe.

Additional Long-Term Structural Monitoring Information

Additional Long-Term Structural Monitoring Information.