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[santhu256]

I have a confusion over the road crossing sections.we are doing petrochemical plant maintenence. We come accross road crossings for various utilities frequently. Mainly for potable water lines electrical line or any other services.We dont have a standerd  detail for the road crossing section. The depth in which sleeve pipes are laid is 900 mm from GL. And its asphalt. So my question is is it very necessary to embed the sleeve pipe in concrete .if so should we reinforce it. Can some one suggest some sections. The biggest vechicle i have seen inside plat is a 300 ton crane.

[es_jayakumar]

In my opinion, it is advisable to either embed the sleeve pipe in concrete or cover it using thin precast RCC slabs. In addition to providing strength to take care of overburden pressure, it will provide identification of the ducts during unintentional excavation at this spot at a later date.

E S Jayakumar

[mallan]

When a Wheel load is applied on the surface, if there is not sufficient depth of soil cover between the pavement and pipe, it will cause very concentrated loads on the brittle pipe, causing it to crack.
Hence for non-hazardous chemicals/water/cabling it is generally recommended to
1. Provide NP-3/ NP-4 RCC pipes
AND
2.a. Provide sufficient soil cover between pavement and pipe to achieve dispersion through soil.
2.b. If not possible to provide sufficient depth of soil, provide encasement.

I donot know about spec for pipelines carrying  hazardous fluids.

You can refer to Bridge Design textbook by Krishnaraju or others for a chapter on design of pipe culverts.

Some government agencies such as PGCIL have standard drawings for such pipe culverts. They may be available on their tender webpages.

-Akshay Mallan

[smstoankur]

You can also use buried soil steel corrugated steel plate pipes which are flexible in nature and can be designed for heavy loading. It is widely used for tunnels and mines in Australia and other countries with haul trucks and other equipment.


Ankur Agarwal