r - The Hong Kong Polytechnic University

The 5th Cross-strait Conference on Structural and Geotechnical Engineering (SGE-5)
Hong Kong, China, 13-15 July 2011
DESIGN OF WIND AND STRUCTURAL HEALTH MONITORING SYSTEM FOR
STONECUTTERS BRIDGE
K.Y. Wong
B.Sc., M.Sc., Ph.D., Eur Ing, CEng, MICE, MHKIE
Bridges & Structures Division, Highways Department,
The Government of Hong Kong Special Administrative Region
E-mail: sebta.bstr@hyd.gov.hk.
ABSTRACT
A wind and structural health monitoring system (WASHMS) is deployed by Highways Department to monitor
the structural performance of Stonecutters Bridge and its environment under the designated performance criteria
at the serviceability limit state. This system at this stage is composed of two major systems, i.e., the structural
health monitoring system (SHMS) and the structural health data management system (SHDMS). The former
system is devised to carry out the monitor works on four categories of physical and chemical quantities in
fifteen types of measurands; whereas the latter system is devised to carry out data operation, data storage, data
retrieval and data interfacing for semis-automatic processing and analysis of data. The four categories of
physical and chemical quantities considered for monitoring are: (i) environment loads and status monitoring
which includes the measurands of wind and weather, temperatures, seismic and corrosion status (in structural
concrete only), (ii) operation loads monitoring which includes the measurands of highway traffics, ship
impacting and permanent loads, (iii) bridge features monitoring which includes the measurands of static and
dynamic features of Stonecutters Bridge, and (iv) bridge responses monitoring which includes the measurands
of stay forces, tendon forces, displacements, stress/force distribution, fatigue damage and articulation responses.
This paper first briefly outlines the equipment types of the installed hardware system and facilities such as
sensory systems, data acquisition systems, cabling network systems and computer systems in SHMS. It then
describes the functional details of the customized software tools for processing and analysis of the
above-mentioned fifteen types of measurands. The customized software tools for SHMS are customized basing
on six aspects of programming consideration, i.e. (i) type of input data, (ii) type of data processing, (iii) type of
data classification, (iv) type of data analysis, (v) type of derived parameters, and (vi) type of plots and/or outputs.
The details of these six aspects of programming consideration for each type of measurands are graphically
interpreted. As the deployment of sensory systems has a strong influence on the methods or strategies of data
processing and analysis, the functional description of the customized software tools are therefore incorporated
with the deployment strategies of the sensory systems. Some typical examples of the monitoring reports are also
included to show the output functions and effectiveness of these customized software tools, and the operation
strategy of the SHMS is also briefly outlined. The hardware and software details of the SHDMS, which is
devised to carry out the operation and management of the huge amount of data generated from the SHMS, are
also briefly described. Finally the conclusions of structural health monitoring are discussed in three aspects, i.e.
summary of SHMS design process, performance criteria for monitoring and nature and functions of SHMS.
KEYWORDS
Structural health monitoring, environmental and status monitoring, operation loads monitoring, bridge features
monitoring and bridge responses monitoring, Stonecutters Bridge.
1. INTRODUCTION
The Stonecutters Bridge is a two-cable plane cable stayed bridge and carries dual-3 highway traffics. It is
currently the world’s second cable-stayed bridge with the main/central span length exceeding 1 km. It has a
9-span configuration of 69.25m+70m+70m+79.75m+1018m+79.75m+70m+70m+69.25m (=1596m). The key
structural features of Stonecutters Bridge are: (i) separated and streamlined steel twin-box girders at central span,
(ii) hybrid (steel/concrete) separated box girders at two side span, (iii) single tower-leg, in which upper part is a
hybrid (steel/concrete) structure and lower part is a concrete structure, and (iv) floating deck connections at
towers and rigid deck connections at all side span piers.
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