Table 2101-1– Flexible reinforcement mesh properties

No Mesh/Net: Requirements

1 Tensile strength of mesh Min 150 kN/m

2 Tensile strength of wire Min 1770 N/mm2

3 Diameter of steel wire/strand Min 3 mm

4 Mesh/Net width (opening size) Max 65 mm

5 Bearing resistance of mesh against punching Min 180 kN

6 Bearing resistance of mesh against shearing Min 90 kN

7 Bearing resistance of mesh against slope parallel tensile stress Min 30 kN

Contractor should get prior approval for the method for fixing of flexible reinforcement mesh and coir mesh

a) Dowels

The dowels shall be of mild steel having mechanical and physical properties specified in Section 1011 and
shall be fully hot-dip galvanized in conformance with requirements of AS1214 (Australian standard for hot
dip Galvanized coatings on threaded fasteners) and AS1650 (Australian standard for coupling assembly) with
minimum coat thickness of 85 microns or 610 gm per meter square surface.

b) Materials Handling and Storage

Cement shall be stored properly to prevent moisture degradation and partial hydration. Cement that has been
caked and lumpy shall be rejected and discard. Rebars shall be stored on firm supports to prevent the steel
from contacting the ground. Damage to the rebar as a result of abrasion, cuts, nicks, welds and weld splatter
shall be cause for rejection. Rebars shall be protected from dirt, rust and other deleterious substances prior to
installation. Heavy corrosion or pitting of rebars shall be cause for rejection. Anchorage end of rebars to
which bearing plate and nuts will be attached shall be protected by some protective wrap during handling,
installation, grouting and guniting.

2101.3 General

a. Method Statement

The Contractor shall inspect the site, study soil investigation results and design details shown in the drawings
before preparation and submission of the method statement to the Engineer for prior written approval (at least
7 days) before the commencement of works. The method statement shall include specific working details
including layout of drilling rig, tools, etc., working platform preparation, temporary support for collapsible
drill holes, drilling, assembling of rebars, inserting of rebar, grouting, nail head preparation and pull-out test,
etc., shall prescribe how to execute the works in working details to comply with the specification and contain
among other things the details of sequence of works, specific type of machines plus necessary staging to be
deployed for drilling and grouting, estimated daily works output rate, necessary quality control
tests/measurements/ observations plus their respective frequency and acceptance criteria. Remedy or
rectification shall also be proposed for cases where the acceptance criteria is not met or achieved. Specific
 operators/ supervisors (name, IC and CV, etc), full details of specific type of rebars plus their protection
system, centralizers, spacers, grout mix details and admixtures and any other materials to be used, etc.,
including catalogues, test certificates and photos of the equipment and materials to be used plus the proposed
machines layout for drilling, grouting and pull-out test shall be shown on drawings and shall also be included
in the method statement. The proposals in the method statement shall meet the requirements shown on the
Engineer’s drawings and this specification hereafter.

b. Trial/preliminary soil nail

The Contractor shall be fully responsible to provide all necessary and suitable resources and materials to
complete all the soil nails strictly according to this Specification. The Contractor shall install the trial or
preliminary soil nails and carry out the verification pull-out test (Clause 2101.5) at locations selected by the
Engineer before commencement of installation of working soil nails. Number Pull-Out tests should be 2 %
of the total number of working soil nails subject to a minimum of two.

2101.4 Construction Requirement

a. Setting out

Setting out shall be as shown in the Drawing or as directed by the Engineer. Immediately before drilling or
installation of soil nail, the nail head position shall be marked with suitable identifiable pegs or markers on
the surface of slope/wall for necessary inspection and checking by the Engineer. The positions of soil nails
shall be checked to ensure any buried utilities, surface boulders, trees and other structures, etc., are not
affected. Engineer’s approval is necessary if the positions of soil nails have to be shifted.

b. Position

The maximum allowable deviation for drill hole entry point shall not exceed 75mm in any direction unless
otherwise approved by the Engineer in writing.

c. Alignment of nail

The drilling machine shall be attached with suitable alignment control devise set to attain the finished nail
direction or inclination shown on the Drawing and the maximum permitted deviation of alignment shall not
exceed 1 in 20. Deviation from straight shall not exceed 20 mm in any 3 m length of drill hole unless
otherwise approved by the Engineer in writing.

d. Nail out of position or alignment

The contractor shall demonstrate to the Engineer that the position and alignment of soil nails is within the
tolerance limits specified. Any nail found out of the tolerable position or alignment shall be rejected and the
Engineer shall order to add additional nails at the Contractor’s own costs.

e. Submittals

The Contractor shall engage a qualified supervisor to prepare and keep records for each soil nail installation
and to submit one signed copy to the Engineer not later than noon of the next working day after the soil nails
have been installed. The record for each soil nail shall include soil nail reference number, date/time of
commencement and completion of drilling and grouting, names of supervisor and operators, plus the
necessary drilling and grouting details, etc. Before commencement of works, format of soil nail installation
records (drilling, inserting of rebar, grouting & nail head construction) and an assembled sample of
galvanized soil nail with MS plate, washers, nuts, coupler, centralizers shall be submitted for inspection,
approval and display at site office. Details about the reputable suppliers/manufacturers of centralizers,
couplers, galvanizer, MS plates, washers, nuts, etc., plus catalogue/test certificates shall also be submitted
for reference and approval of the Engineer.
Drilling Records for each nail shall include:

 Soil nail reference number & design working capacity