road slope erosion: preventive & corrective solutions by envirotac

Method Statement

Road Slope Erosion :

Preventive & Corrective Solutions

Project Location:

Northern Ring Road – Al Ain

SOROCON (EP&A Envirotac, Inc. Rep) – Eastern Region Emirate of Abu Dhabi

Prepared by: SOROCON Engineering Department. For additional info;

Eng. Walter Schutte

O�ce - 760-777-8035 Mobile - 909-908-3052 Email - [email protected]

TABLE OF CONTENTS

1.0 INTRODUCTION PAGE 3 2.0 SITE SURVEY PAGE 4 - 5 3.0 PROJECT PARAMETERS PAGE 6 - 7

4.0 ILLUSTRATION OF PROJECT PARAMETERS PAGE 8 - 10 5.0 ESTIMATED PROJECT VOLUME PAGE 11

6.0 PRICING & WARRANTIES PAGE 11 7.0 IMPORTANT NOTE PAGE 11

1.0 INTRODUCTION:

Road slopes in general are exposed to the elements and may suffer from severe erosion and soil displacement specifically during heavy rainfall. Depending on the road height, slope angle and materials used, these areas deteriorate rapidly if not properly stabilized or covered/planted. Such erosion and displacement can be avoided by simply spraying and saturating the top 1inch to 1.5inch of the slope surface with ENVIROTAC II during the construction phase of the slope.

Pictures above and below of road sections along the Northern Al Ain Ring Road are taken by Eng. Mariam Saeed Marah Al Alawi – Material Engineer and Project Manager at the Material QC Section, Internal Roads & Infrastructure Department.

2.0 SITE SURVEY: A thorough survey was conducted on Wednesday, April 25, 2013, at the north-west slope of the Northern Ring Road in Al Ain, at a length of approximate 5 Km.

Survey Start point: 24 22 15.87N 55 47 41.29E (at bridge over Wadi)

Survey End Point : 24 20 04.34N 55 45 58.13E (at Power Station)

Start Point

Approx. 5 Km

Severely eroded road slope: heavy rainfall has displaced the soil from upper section to bottom of slope.

Guard Rail Poles causing surface water turbulence at run-off and severe soil displacement at pole-base.

3.0 PROJECT PARAMETERS: With reference to the conducted site survey, the slope work is identified as corrective (severe erosion already occurred), and the execution shall therefore include the following procedures and equipment:

Secure work area with safety cones and flag-man. (roadside area only)

Remove soil at top of slope at a depth of 10cm to 15cm, at a width of approximate 1 meter from road (asphalt) edge, using a Compact Excavator positioned in the slope, and use the removed soil as fill where erosion has occurred on lower parts of the slope. (see cross sections on pages 8 and 9)

On site mixing of ENVIROTAC II/H2O with in-situ soil using a mobile self-loading mixer. Transport of ready mixed material to top of slope using a compact track loader

Mobile self loading mixer Compact track loader

Fill the upper slope section with ENVIROTAC II/in-situ soil mixture using a compact track loader and manual labour. (surface compacting as a whole not necessary, only where the soil is replaced, using a hand-held plate compactor)

Hand-held plate compactor

Level the untreated soil over the whole slope area, including the displaced soil at bottom of slope using a Front Loader.

Spray at least 2 layers ENVIROTAC II/H2O mixture on the whole slope surface using modified vehicles and equipment detailed in page 10.

4.0 ILLUSTRATION OF PROJECT PARAMETERS:

remove approx. 1m of top-soil at

10cm to 15cm depth

Asphalt Road Base Aggregates Guard Rail Pole

replace approx. 1m of top-soil with

mixture in-situ soil/ENVIROTAC II


Level the untreated soil to bottom of slope. Compact the mixture in-situ soil/ENVIROTAC II using a hand-held Plate Compactor.


Spray ENVIROTAC II/H2O mix on the entire slope. (at least 2 layers)


Alu beam: min. 2.5m max. 4.5m (depending on slope area and slope angle)

Approx.3.5m 4.5m

7 Ton Truck with Crane Removable Aluminium Unit Beam attached to truck rear-end for slope-spray device.

ENVIROTAC/H2O Totes (1,000 ltr. each)

Compact Track Loader for slope repair up to 45% slope angle.

Removable Aluminium Unit Beam attached to truck rear-end

2.5inch water-hose connected to pump and tote

Road Safety Cones

7 Ton Truck with Crane

5.0 ESTIMATED PROJECT VOLUME:

Of the surveyed length of approximate 5 Km, at least 4.5 Km need to be repaired and stabilized. As the width of the slope varies, we have estimated 8 meters as an average from top slope to unpaved service road edge at the slope-base; however we recommend re -measurement upon completion. Project Volume: 36,000 m 2

Recommendation:

Please note that upon completion of the stab ilization works, the slope surface permeability will be reduced substantially, and therefore any surface water during heavy rainfall might cause severe damage to the unpaved service road at the slope -base. If the unpaved service road is presumed to be permanent, we highly recommend to stabilizing also this area with ENVIROTAC II at a width of at least 4.5 meters measured from the slope -base , and at a depth of 10 cm.

road slope erosion: preventive & corrective solutions by envirotac

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