Design and Construction of Collections system
|Contractor:||KOLON GLOBAL CORPORATION, KOREA|
|Contract Cost:||YEN MILLION||3,698|
|Start Date:||26th November 2013|
|Finish Date:||31st October 2018|
The contract package number 02, involves the design and construction of a wastewater collection system including manhole type sewage pumping stations and the procurement and delivery of specialized sewer maintenance vehicles and equipment.
The work includes trunk sewers, branch sewers and service connections sewers up to terminal connection points named Interceptor Chambers (IC) located at each property within the proposed sewer service area. Several manholes will be needed to ensure smooth flow of sewer along the pipelines.
Existing treatment plants at hotels, industry and at two hospitals (Kandy General and Peradeniya Teaching Hospitals) are presumed to be maintained to provide pre-treatment before discharging to the collection system. Given below are the details of pipes and manholes to be constructed under this contract.
|Sewer Type||Length (km)|
Pipe laying details by Road Authority (Trunk & Branch Only)
|Road Authority||No of Roads||Length (Km)||No. of Manholes|
|Road Development Authority (RDA)||22||21||459|
|Provincial Road Development Authority (PRDA)||7||6||189|
|Kandy Municipal Council (KMC)||169||53||1864|
|D S Senanayaka Mawatha||826|
|Sirimawao Bandaranayake Mawatha||2568|
|SWRD Bandaranayake Mawatha||346|
|Thilak Rathnayake Mawatha||423|
|William Gopollawa Road394||394|
|Sarasavi Uyana Road||202|
|Sirimawo Banadaranayaka Mawatha||150|
|D S Senanayaka Mawatha||289|
|Sirimawo Banadaranayaka Mawatha||775|
|H B Udurawana Mawatha||108|
|Sirimawo Banadaranayaka Mawatha||897|
|SWRD Bandaranayake Mawatha||90|
Service Area & Pipe Network
Pipe laying methods
- Open Cut
Open cut trench excavation is the traditional and most popular method for sewer pipe construction. Open cut trench excavation consists of excavating a trench for the manual installation of each piece of pipe. This method is usually the least expensive method if the pipe is located under non‐pavement areas. The open cut trench method involves excavating down to required level and lay the pipes and then backfilled.
It is a worldwide trend today to adopt the trenchless methods rather than the open trenching method. Especially in urban areas where the open trenching causes disruptions to the traffic and affects normal operations of existing underground utilities. Such public nuisances are not tolerated by the people, even for public works construction which will surely result in a better living for themselves. As a solution to minimize inconveniencing the public due to pipeline construction works, this high-tech construction method is used. Trenchless method uses a special type of tunneling machine which is being remotely controlled from the operation section located outside in a large pit. The tunneling machines are located in the driving pit. Pipes are pushed under the ground with the help of the tunneling machine. The crushed materials due to the excavation works of the front head of tunneling machine, are transported to the outside through a discharging line. The crushed material are divided into slurry and soils by the treatment equipment on the surface.