International research indicates that clients, designers, project managers, and quantity
surveyors influence and can contribute to H&S.
<br>The promulgation of the South African Construction Regulations in July 2003 has
realised client, designer, and quantity surveyor responsibility for H&S. Clients are required
to - inter alia - provide the principal contractor (PC) with an H&S specification and ensure
that PCs have made adequate allowance for H&S. Designers are required to - inter
alia - provide the client with all relevant information about the design, which will affect
the pricing of the works, inform the contractor of any known or anticipated dangers or
hazards, provide the contractor with a geo-science technical report, and the methods and
sequence of construction, and modify the design where dangerous procedures would be
necessary, or substitute hazardous materials.
<br>Given the implications of the Construction Regulations, and the opportunity presented
by the presentation of a national series of Construction Regulations seminars, a survey
was conducted to determine the perceptions of primarily engineering delegates.
<br>Findings include that: contractors predominate in terms of the perceived extent to
which stakeholders can contribute to H&S; the implementation of quality management
systems (QMSs) would complement construction H&S; client satisfaction predominates in
terms of the importance of various project parameters, followed by quality, cost, and time;
productivity and time predominate among parameters negatively affected by inadequate
H&S; approximately 61 % of respondents stated that the Construction Regulations would
result in between an improvement to major improvement / major improvement in H&S.
The paper reviews human thermal comfort scales for naturally ventilated buildings. It
compares the neutrality temperatures based on the new effective temperature (ET) with
that based on the dry bulb (DB) temperature and provides the motivation why the DB
base is preferable, given the relatively favourable South African climate conditions and
the ease of calculation. It also investigates the most recent research developments in
adaptive comfort neutrality temperatures and their ranges. These are applied to South
African conditions to produce realistic and cost-effective target design temperatures for
naturally ventilated buildings of two classes of stringency.
To evaluate the liquefaction potential of tailings impoundments, the in situ void ratio and
the effective stresses are required. While stresses can be estimated with relative accuracy,
the void ratio of tailings has proved difficult to obtain, especially below the water table.
The development of in situ seismic techniques has presented new opportunities to
determine the in situ void ratio of geomaterials. In addition, these seismic methods can
be used to evaluate the liquefaction potential of gold tailings. However, the method
currently relies on the shear wave velocity-void ratio relationships developed for sands,
while gold tailings is essentially a silty material. This raises the question of the validity of
such relationships for tailings material. A triaxial apparatus was modified to accommodate
bender elements and the shear wave velocity of gold tailings was determined at various
void ratios and effective stresses. The results show that there is a relationship between
void ratio and the normalised shear wave velocity of gold tailings. They also show that the
shear wave velocity for gold tailings is more sensitive to changes in effective stress than
to changes in void ratio and that the shear wave velocity is virtually independent of the
overconsolidation ratio. Application of the shear wave velocity-void ratio relationship in
conjunction with critical state theory indicates that at the same shear wave velocity, gold
tailings have a lower susceptibility to liquefaction than sands.