SUMMER TRAININGLAYING OF SEWER LINERAMPUR SEWERAGE SCHEME ZONE (V)UTTAR PRADESH JAL NIGAM, A U.P GOVT. UNDERTAKINGCONT: M/s LARSEN & TOUBRO

RAMPUR

Small city in the north western zone of Uttar Pradesh. Population of almost 2,80,000. Ramganga, a subsidiary of Ganga River passes through the city. Approximately 11,000 million liters per year waste water from

Rampur is directly disposed into Ramganga river which is indirectly transferred to Ganga river.

Under the new development scheme of Uttar Pradesh government, the state will make around 200 small/ big sewage treatment plants in the near future.

Works have started in major cities like Agra, Moradabad, Rampur, Varanasi and many more.

BASICS

Worked as an industrial trainee under Uttar Pradesh Jal Nigam for a tenure of almost 6 weeks.

To lay 14.5 km sewer line throughout rampur. Construction of 5 mld sewage treatement plant based on SBR (

sequential batch reactor) technology. Initial project cost: 58 crores Project tenure: 14 months Contractor: M/s Larsen & Toubro

SCHEMATICS

PLANT

Based on SBR technology. Maximum capacity of 5mld SBR tech provides highest treatment efficiency in a single step

biological process No additional settling unit or secondary clarifier is required. SBR technology has a good operating flexibility and control Due to its compact design, it requires very less area as

compared to other conventional STP’s. Highly economical, eliminates the cost of clarifiers and other

equipment.

ZONE V Zone V was a 4.5 km stretch With the help of population forecasting for the next 30 years,

the discharge was calculated and according to that the diameter of the pipes used and design capacity of the plant was selected

Manning's equation was used to determine the required slope. With the help of the equation and discharge to be carried a

slope of 1:800 was to be provided in the 4.5 km stretch This implies that for every 800m a drop of 1m was to be given.

SPECIFICATIONS• As per the design, pipe selected were of 2.5m in length and

600mm in diameter.• For the zone V stretch of 4.5 km , if we do the math…….• No of pipes needed = 1800 pipes• For the slope of 1:800, each pipe would go a 3mm drop .

PIPES• Made of Reinforced cement concrete as per Indian Standards• Pipe length= 2.5m• Inner diameter = 600mm• Thickness = 85mm• Head thickness = 85mm• Total thickness at the head = 85+85+600 =770mm• Total thickness at tail = 600+85 = 685mmADVANTAGES:• Equally efficient in handling tension & compression• Long service period• Can be casted of desired strength

PROCESS

Approach, population forecasting, design & calculations

Taking levels Excavation

Bedding material, ramming, laying of pipes, joining of pipes

Manholes, filling back the trench

LEVELS• Simple Auto Level and a telescopic staff were used• Levels were taken for1. Natural ground level2. Depth of trench3. Top of bedding material4. Top of pipe surface

EXCAVATION• Use of Komatsu excavator with a bucket capacity of 1 cubic

meter to dig trenches• 30-40 cm spacing on either side of pipe is ensured for the

labors to work• If depth of trench marginally increases use of telescopic

excavation is done for economical purposes.

SHORING BOX• Stabilizes the trench walls from collapsing• Can withstand high earth pressure and drastically reduces the

probability for any accident due to trench wall instability• Helps protect adjacent structures and their foundations• Helps in controlling GW seepage thus aiding in progress of work

MOULD AND MATERIAL• To provide a strong base for the pipe a concrete mix of 192mm

height was provided• Wooden mould: 1x1m with 192 mm depth• Bedding material was being prepared in a electrical concrete

mixer• Mix used was of 1:2:4 ratio i.e. 1 part of cement with 2 part of

sand and 4 parts of coarse aggregate.• Material was prepared by a handful of labors not too far away

from the excavation site.

PROCESS

PLACING OF PIPES

• After bedding material was placed readings were taken to ensure correct bed depth else more ramming was done to ensure that.

• Pipes were lifted and placed with the help of excavators• Placed on the bed and then readings were again taken of the

top of pipe after joining with the existing section• Readings were taken to ensure the 3mm drop per pipe• The pipes were pressed by the help of excavator to make any

changes in the readings

PROCESS

JOINTS• Pipes were sealed with the help of a rubber gasket• Rubber gasket provides adequate water tight sealing solution.• External sealing was done with jute ropes dipped in liquid

cement solution.• Jutes ropes are cheap, easily available and no additional

skilled labor is required for the job• The cement dipped jute rope hardens with time to provide

excellent sealing properties.

MANHOLES• In the Zone V manholes were provided at every 30m interval.• Manholes are basically provided when• Change in diameter• Change in alignment• Change in slope• Maintenance purposes

• Manholes are also used as inspection chambers .• In case of clogging of the pipe manholes play a important role

in making the line operational again.• In Zone V, the manholes were constructed by the masons.

MANHOLES

ADDITIONALS

• Other than on site work, I was also introduced to rate analysis of the work, the charges , contractor profit sums etc.

• All the readings of the level were carefully noted in a maintained register.

• All the calculations were done mostly on site by the Junior Engineer from both L&T and U.P Jal Nigam.

• The materials used were also inspected thoroughly by the engineers on site before use to ensure quality.

SAFETY• Complete barricading of the road was done with TIN sheets

and plastic tapes so as to provide a safe environment both for the workers and traffic around the site

• Caution boards, sign plates, night flood lights were used as additional safety features.

• Safety jackets safety boots and safety helmets was must for every worker on the site.

CONCLUDING……• Introduced to the process of design of sewerage scheme for a

town or a city• Developed a good skill in taking readings from the auto level• Learnt how to lay sewer pipes • Also learnt about site safety and precaution measures• Learnt about use of moulds, shoring boxes, manholes etc.• Was also introduced to office rate analysis work• Learnt how to maintain a measurement book• At last It was a good learning environment as it helped me

improving my skills.

THANK YOU