Field Survey, Detailed Study and Geotechnical Investigation for Construction of 1#-14# Bridge and 1030m Subgrade / Road Slope Stability at Kathmandu- Terai/Madhesh Fast Track (Expressway) Road Project

Project Details

The main purpose of the field survey works is to develop survey map of area, preparation of meteorological data sheet, identify hydrological and hydraulic condition of river at proposed bridge sites, investigate probable seismic hazard of proposed bridge and geotechnical investigation of Mahuri Bhir Slide, Bridges and Subgrade is to investigate the subsurface geological conditions, presence of ground water, thickness of rock bands, depth of over burden, etc. The geotechnical investigation for Bridge and Subgrade / Road Slope Stability comprises of 31 boreholes. The maximum depth of geotechnical exploration is 171m.

The main field investigation works include:

1. Preparation of Survey Map including

• 1:2000 Scale Topographic Survey Map along Tunnel line – 3.2 km²
• Forth-grade Control Points survey layout – 10 Nos
• First-grade Control Points layout – 10 Nos
• Profile Survey – 6.75 km
• Cross-Sectional Survey – 675 Sections
• Riverbed Section Survey – 12 Nos

2. Meteorological Survey

• Annual Rainfall Study, Wind Speed Study, Temperature Study

3. Hydrological, Hydraulics and Scour Survey

•  Study of Catchment Characteristics
• Design Flood
• Sediment Yield
• Hydraulic Simulation
• Hydraulic Design
• Scour Calculation
• River Protection

4. Seismic Hazard Assessment of Bridge and Project Area

• Seismo Tectonic Data Analysis
• PSHA Model and Analysis
• Design Response Spectra Analysis

5. Geological Mapping of Area in 1:2000 Scale – 1.5 km²
6. Geotechnical Investigation (drilling works and laboratory tests) is to investigate the subsurface geological conditions, water pressure (Lugeon Test for permeability), presence of ground water, thickness of rock bands, depth of overburden,etc.

The detail of drilling and testing works is listed below: