Civil Engineering Reference
In-Depth Information
Fig. 5.1
Examples of hazardous defects.
(6) Deficiency of design and construction
Excessive stress and careless construction details are common faults in structural design.
During construction, the most common quality defects include loose joints, deficient mem-
ber strength caused by dimension errors, rickety roof-truss joints, split members and insuf-
ficient constructional requirements for mortises, etc.
5.1.2
Principles of Wood Structure Retrofitting
The methods of wood structure construction vary by locations and ages. Accordingly
different strengthening methods are adopted in different districts or projects. There is no
certain set of methods to follow. On the premise of meeting service demands, the strength-
ening method should consider local conditions and eliminate hazards economically so as to
make the wood structures safe for service. The main points of retrofitting are as follows:
(1) Reliability assessment
Before strengthening, reliability of the original structure and members should be assessed,
and service conditions of structure and material should be investigated. The contents in-
clude:
