Code of practice for planning and design of ports and harbours, Part 1: Site investigation
1974 Edition

IS 4651 Part 1 prescribes the following soil exploration methods for port foundation design: Main boreholes should be located along the shoreline edge at intervals of approximately 50 meters and drilled to a depth of either 3 meters into hard strata or twice the elevation difference (2H) across the site. Large diameter boreholes are recommended in reclaimed or boulder-laden zones. Intermediate borings supplement main boreholes to capture detailed stratigraphic variations. Data from field tests such as Standard Penetration Tests and lab analyses including grain size distribution and consolidation parameters are compiled to characterize the soil profile comprehensively.

The code advises obtaining long-duration tidal records, preferably spanning a 19-year Metonic cycle, from authoritative sources such as port authorities or hydrographic departments. Site-specific data including tidal bores must be included. Current measurements require monitoring velocity, direction, and duration continuously over full tidal cycles during spring and neap tides for at least a year. Depth-wise readings at 10%, 50%, and 90% of water depth are recommended. For riverine ports, peak flood current assessments are essential. Additional parameters like suspended sediment load and salinity are sampled hourly during tidal cycles across similar depths, while sea water temperature is also documented.

The standard identifies wind velocity and direction as primary meteorological parameters, requiring continuous recording over a minimum one-year period with self-registering anemometers. Monthly wind rose diagrams illustrating directions and frequencies, combined with velocity data, are to be prepared using the Beaufort scale. Other essential parameters include relative humidity, temperature, and barometric pressure. Additionally, site designation details such as geographic coordinates, altitude, and surrounding terrain features are recorded to support environmental load calculations.

While IS 4651 Part 1 itself focuses mainly on site investigation and does not directly address seismic design, it provides crucial soil and geotechnical data necessary for seismic analysis. Seismic design requirements, including determination of acceleration coefficients and dynamic soil-structure interaction, are covered under IS 1893 and IS 4651 Part III. The investigation includes gathering historical seismicity, soil properties, and site-specific parameters to aid in evaluating seismic hazards and designing foundations and superstructures capable of resisting earthquake forces.

The standard stresses the importance of assessing local resources such as labor availability, material supplies, and equipment near the construction site to optimize project cost and scheduling. It recommends cataloguing types and quantities of materials like bricks, stones, and timber, along with quarry locations and transport facilities. Labor assessments include skill levels, numbers, and prevailing wage rates. Availability and hiring rates for machinery are also documented. This comprehensive resource evaluation supports realistic planning and efficient construction management aligned with site-specific conditions.