L-Section GPR Survey for Cable & Pipeline Routes

Rates and page checked: 23 October 2026

What is an L-section GPR survey?

Think of an L-section (longitudinal section) as the ground sliced lengthwise along a route and viewed from the side. An L-section GPR survey uses radar scanning to build that side view for the services under your planned alignment: each water main, sewer, gas pipe, duct or cable detected along the way is shown at the depth where it was found.

A standard survey answers the question "where is it?" in plan. The L-section also answers "how deep is it, all the way along?" – which is what a designer asks when setting the laying depth of a new cable or pipe and deciding where it must dip or rise to pass existing services. Contractors who search for GPR profiling services for a specific route usually need exactly this.

The profile can only show what radar reaches. How far it reaches depends on soil and moisture: moist clay and salty ground cut it down, while dry sand lets the signal go further, and our report notes, stretch by stretch, how deep the radar got.

When do contractors need an L-section?

Not every job does. The profile earns its extra ₹8 per metre in situations like these:

• the work order or tender asks for an L-section drawing for the cable route to be submitted along with the survey;
• the route runs through congested streets where the new line must pass over some services and under others;
• part of the route will be laid by HDD, and the bore has to clear existing services;
• a pipeline or duct must hold a gradient, so depth along the full length matters;
• the client wants a record of what lay beneath the route before construction.

Where the job is a simple land survey for underground electrical cabling along open rural verges with few services, the standard survey is usually enough. Not sure which one your contract needs? Send us the survey clause and we will tell you plainly.

How does it differ from the ₹24/m standard survey?

Field work is planned differently when a profile is required, so it is better to order the L-section at the outset than to add it once a standard survey has been completed.

What does an L-section GPR survey cost?

The rate is ₹32 per running metre, or ₹32,000 per kilometre. A few rules shape the final figure:

• Minimum length: 4 km per order, so the smallest L-section job is billed at ₹1,28,000. That already clears the ₹1 lakh project minimum that applies beyond Delhi NCR.
• Volume slabs: once the full order goes beyond 100 km, the rate becomes ₹24/m; beyond 500 km, ₹19.20/m; beyond 1,000 km, ₹16/m. The lower rate covers every metre, not just the extra ones.
• Taxes and extras: GST is added separately. Mobilisation, night-shift working, traffic arrangements or permissions, and CAD/GIS drawing sets sit outside the per-metre rate and are quoted on their own.

As an example, a 50 km cable route costs ₹16,00,000 with the L-section against ₹12,00,000 for the standard survey, both before GST. The GPR survey price list sets out every rate and slab.

How do you order an L-section survey?

1. Send the route as a KML file or marked drawing through our quote form, with its approximate length.
2. Tell us what the route is for – HT/LT cable, OFC duct, water or gas pipeline – and whether any part will be bored.
3. Share the clause in your work order that describes the survey or L-section required.
4. We reply with a quote showing the ₹32/m rate, any slab, minimums and separately priced items, plus a working programme.
5. Crews mobilise from Faridabad with company-owned GPR systems and start on the stretches you need first.

For power cable jobs, the HT/LT cable route survey page explains the full route survey this profile is built on. Contractors in central Gujarat can use our Vadodara L-section page, and our article about L-section requirements on DISCOM cabling jobs discusses how these profiles are used on distribution projects.