INGENIEUR
a Figure 4.1 : ( a ) Setting out work and ( b ) alignment control
b and sedimentation control plan ( ESCP ). Hence , proper runoff management during earthworks and construction activities can be carried out at project sites without detriment to the existing ground which can contribute to the erosion and sedimentation problems .
The construction of BIOECODS has posed several challenges to the designers and site supervision teams in terms of striking a balance between the department ’ s green policy and minimum design as per guideline and the local authority ’ s requirement , modification due to site constraints , best management practices and procurement methods .
Alignment Control Setting out is the first work to take place in the construction of BIOECODS at the project site . The location and the alignment of the swale will be determined , followed by levelling survey to avoid misalignment to the connecting downstream swale . The invert level of the swale will be marked along the drainage alignment so that the excavation work will be properly done . The alignment control is important as improper alignment will increase the construction and maintenance cost of other infrastructure or utilities at the adjoining land . Without proper alignment , preferred shapes of swale cannot be appropriately constructed . Figure 4.1 shows the setting out and survey work at the project site .
The work sequence , best management practice and maintenance procedure need to be clarified to the contractor . The alignment of the swale must be co-ordinated with platform level , road level , road crossing , sewerage system alignment ( sewer pipe and manhole location ), domestic and hydrant pipe alignment . The alignment must also consider the landscape requirement in terms of open space and green area . Therefore , the site supervision team must ensure that the swale is not turned into a dumpsite during or after the construction stage . The alignment of the swale must be marked clearly before work commences and must be protected with signboards and a silt fence . The contractor shall also submit a method statement on the construction process of swale and obtain material approval before the construction of BIOECODS .
Utility Clashing
Figure 4.2 : Clashes between TNB power supply cable and swale module invert level
64 VOL 88 OCTOBER-DECEMBER 2021