EFFECTIVE STEPS TO FOLLOW IN MATERIALS INVESTIGATION FOR A PROJECT

Introduction

 In a road or an earth dam project, earth works form a big chunk of the works. For instance, in a road project there is need to have suitable material for fill, sub base and base while in an earth dam the same is required for the core, shell, blanket filter and rip rap. Ideally it would be reasonable to use the cut material for fill however practically there is still a huge deficit. It is therefore important to prepare a mass balance diagram (to be covered separately on this blog) to establish your material needs. As a result the material is investigated closest to the project area in order to reduce haulage costs. Materials Prospecting is not an easy task, just imagine you are looking for about 100,000m³ of suitable material for a 100Km road project. It is against this background that this article is written to help with some practical steps to  effectively investigate materials for a project. The steps suggested have effectively worked for the author and he hopes they also do for you.

Step 1: Estimate the Net Volume of Earth Works Required

I will use a hypothetical data of a 5km section of a road project and assume the material being investigated is fill

Start by drawing a schematic representation of the road and indicate the material cut, volume of fill, volume of cut materials which is suitable for fill and the net required fill within the first 5 km, see an illustration below

Cut	10m3
Chainage	0 +000	5+000
Fill	12m3
Cut Material Suitable  for Fill	2m3
Fill Required	10m3

Note: The suitability of the Cut Material for fill is established by testing the material on the center-line of the road every 500m.

Step 2: Mark a 10Km Radius on Google Earth or Map around your Project Area and Establish Hints for availability of the Materials

·         Observe Land Use and Vegetative Cover . Gravel is associated with shrubs and stunted growth of crops. This can be established by using Land Use Database for Malawi available at Land Resource Conservation Department and Google Earth

·         Observe Topography. Naturally as you approach rivers in a highly hilly area there is likelihood of finding gravel due to weathering of rocks.

·         Observe if there is existing infrastructure that used materials of similar nature i.e. existing road, earth dam etc and establish the borrow pits used previously

·         Use available Local Knowledge. Locals have an idea where gravel material can be found

If there is no or insufficient gravel within the 10 km radius then draw  15 km radius and so forth.

Step 3: Resource Planning

Before you set off for the field trip please plan in advance the resources you will need for materials investigation. The resources required are as follows: Sample Bags, 4x4 Vehicle, Materials Technician, Driver, Casuals, Handheld GPS, Hoes, Shovels, Safety Gear ( Safety Boots, helmet, gloves, mask, goggles and snake gutters), tape, strings and notebook

Conclusion

This article has looked at some of the important steps to bear in mind when prospecting material for construction project. In the subsequent posts the author will provide you with other pertinent tips on materials investigation.