REQUEST FOR PROPOSALS

delineation of segments homogenous with respect to roughness and strength
should be done using the cumulative difference approach (AASHTO, 1993).
2. The data on soil classification and mechanical characteristics for soils along the
existing alignments may already be available with the PWD. The testing scheme
is, therefore, proposed as given under:
i. For the widening (2- Laning) of existing road within the ROW, the Consultants
shall test at least three sub-grade soil samples for each homogenous road
segment or three samples for each soil type encountered, whichever is more.
ii. For the roads along new alignments, the test pits for sub grade soil shall be
@5km or for each soil type, whichever is more. A minimum of three samples
should be tested corresponding to each homogenous segment.
3. The testing for subgrade soil shall include:
i. in-situ density and moisture content at each test pit
ii. field CBR using DCP at each test pit
iii. characterisation (grain size and Atterberg limits) at each test pit and,
iv. laboratory moisture-density characteristics (modified AASHTO compaction);
v. laboratory CBR (unsoaked and 4-day soak compacted at three energy levels)and
swell.
4. For problematic soils, the testing shall be more rigorous. The characteristics
with regard to permeability and consolidation shall also be determined for
these soils. The frequency of sampling and testing of these soils shall be
finalised in consultation with the NHIDCL officers after the problematic soil
types are identified along the road sections.
5. The laboratory for testing of material should be got approved from NHIDCL
before start of work.
4.11.4 Investigations for Bridges and Structure
4.11.4.1 Inventory of Bridges, Culverts and Structures
The Consultants shall make an inventory of all the structures (bridges, viaducts,
ROBs, /RUB and other grade separated structures, culverts, etc.) along the road
under the project. The inventory for the bridges, viaducts and ROBs shall
include the parameters required as per the guidelines of IRC-SP: 35. The
inventory of culverts shall be presented in a tabular form covering relevant
physical and hydraulic parameters.
4.11.4.2 Hydraulic and Hydrological Investigations
1. The hydrological and hydraulic studies shall be carried out in accordance with
IRC Special Publication No. 13 (“Guidelines for the Design of Small Bridges and
Culverts”) and IRC:5 (“Standard Specifications & Code of Practice for Road
Bridges, Section I General Feature of Design”). These investigations shall be
carried out for all existing drainage structures along the road sections under the
study.
2. The Consultant shall also collect information on observed maximum depth of
scour.