In short: DATA PKT is a landslide and slope stability investigation company. We combine three independent data sets in one ground model: drone LiDAR for the shape of the slope, seismic refraction tomography for what lies below the surface, and geological mapping for how the soil and rock behave. A stability analysis turns that model into a factor of safety for every critical section, and we design the protection each stretch needs.
Why slopes fail, and why one method is not enough
Most slope failures along Indian hill roads and railways come from a few mechanisms: shallow slides in soil and weathered rock after heavy rain, erosion and scour at the toe, and rock blocks sliding or toppling along joints. Each needs different information. A terrain model shows the geometry but not what is underneath; a borehole shows one point; a geologist sees the rock face but not its depth. That is why we combine the methods below and check them against each other.
What we do
1. Drone LiDAR survey and 3D models
RTK/PPK drone LiDAR tied to DGPS ground control captures the slope and the road edge, even under vegetation. Multiple laser returns let the point cloud be classified into ground and vegetation, so we deliver a bare-earth digital terrain model (DTM), a surface model (DSM), contours, an orthophoto, slope-angle and aspect maps, longitudinal and cross-sections, and 3D models of critical stretches. See LiDAR survey.
2. Seismic refraction tomography (SRT)
A line of geophones (typically 24 channels) is laid on the slope or road edge and a hammer source is struck at several shot points along it. First-arrival times are picked and inverted into a P-wave velocity section that shows the thickness of loose cover, the depth to weathered and fresh rock, and low-velocity zones that are weak or saturated. Every profile is positioned by DGPS so it plots directly on the LiDAR cross-sections. See seismic refraction survey.
3. Engineering geological mapping
Geologists map lithology and structure at the critical locations, measure joints by scanline and window surveys, test strength in the field with a Schmidt hammer and point-load tester, and classify the rock mass with RMR, GSI and SMR. Stereonets and kinematic analysis show which failure modes are possible: planar sliding, wedge sliding or toppling.
4. Strength parameters
Shear strength (cohesion c′ and friction angle φ′) is derived from GSI and field strength through the generalised Hoek–Brown criterion, with Barton–Bandis for joints, cross-checked against the SRT velocities. Laboratory tests on borehole samples are recommended for the most critical sections.
5. Slope stability analysis
Limit-equilibrium analysis (Bishop, Spencer and Morgenstern–Price methods) gives a factor of safety for each critical section in three cases: dry, saturated (monsoon) and earthquake (pseudo-static, with the seismic coefficient for the site's IS 1893 zone). Rock slopes are also checked for planar and wedge failure.
6. Hazard zonation and protection design
Every stretch is ranked Low, Medium, High or Critical, so the owner knows where to act first. For each stretch we recommend and design protection matched to its failure mechanism:
| Problem found | Typical protection we design | Key inputs from the investigation |
|---|---|---|
| Water in the slope, saturated soil | Surface and sub-surface drainage, weep holes, catch-water drains | Seepage points, saturated case factor of safety, LiDAR drainage paths |
| Shallow slides in soil and weathered rock | Soil nails with flexible high-tensile mesh, re-grading, vegetation and erosion-control mats | Thickness of loose cover from SRT, c′ and φ′, slope geometry |
| Rock blocks on joints | Rock anchors and bolts, cable nets, rockfall drapes | Joint sets and kinematics, block size, depth to competent rock |
| Rockfall from higher slopes | Rockfall barriers and catch fences located on trajectory analysis | Source zones from mapping, fall-line profiles from LiDAR |
| Toe erosion and scour beside rivers | Toe walls, gabions, river-training measures | Toe profile, scour-prone sections, flood levels |
What you receive
- Classified point cloud, DTM and DSM, contours, orthophoto, slope-angle maps, cross-sections and 3D models (LAS/LAZ, GeoTIFF, DWG/DXF, SHP, OBJ, KMZ)
- SEG-2 field data, velocity tomograms with interpretation and depth to competent strata for every SRT profile
- Geological plans and sections, discontinuity database, stereonets, RMR/GSI/SMR sheets and strength parameters
- Stability analysis for each critical section, hazard zonation map and priority list
- Protection design: concept and design drawings, design parameters and quantities for each stretch
- An integrated report with all data on a drive, in your coordinate system
Standards and practice
DGPS control tied to Survey of India or CORS; LiDAR accuracy reported against independent check points (ASPRS); discontinuity surveys to IS 11315; point-load testing to IS 8764; RMR to IS 13365; seismic zones and coefficients to IS 1893; roadside work-zone safety to IRC:SP:55; drone operations under the Drone Rules, 2021 with Digital Sky permissions.
Where this matters
Hill roads and railways in Assam, Arunachal Pradesh, Meghalaya, Nagaland, Manipur, Mizoram and Sikkim, the Himalayan states, the Western Ghats and the Nilgiris; tunnel portals and cuttings; hydropower, transmission and pipeline corridors through hills. See our work in Northeast India.
Case study
For a private client we investigated the road-side slopes of a ~66 km corridor in Assam: drone LiDAR of the full length, 66 seismic refraction profiles, detailed geological mapping at 7 locations, and a stability report with stretch-wise hazard ranking and protection design inputs. Read the full case study.