Grout curtain

Research on the topic Grout curtain "Ground water" . Among the topics of Sanitary Engineering

1. curtain grouting BAGHDAD UNIVERSITY SANITARY ENGINEERING DEPARTMENT M.Sc. student : Marwa Mohammed

2. WHAT IS GROUTING? Grouting is carried out for ? Type of GROUTING? Ground Water Control General Applications of Grouting

3. WHAT IS GROUTING? Improvement of soil or rock through injection of grout, cement or chemical grout . Grouting may be divided into following :- Intrusion grouting Compaction grouting Permeation grouting Jet grouting Compensation grouting

4. (1) to reduce leakage under the dam (2) to reduce the uplift pressures, (3) to strengthen jointed rock foundations. Grouting is carried out for three reasons:

5. To these ends, there are two types of grouting that are carried out at most dam sites: 1- consolidation grouting 2- curtain grouting The purpose of consolidation grouting is to strengthen the foundation rock. It is carried out with low injection pressures in shallow holes, with the aim of sealing major crevices and openings.

6. Curtain grouting is designed to reduce both leakage and uplift pressures. Grouting is carried out at higher injection pressures in holes up to 100 m deep. The curtain is usually created with a single or double line of holes located near the heel of the dam and aligned parallel to the dam axis.

7. The joints or fractures in soil or rock are filled with injection of grout Pipes are first inserted into the soil from surface and than the grout is added with pump Advantage is, it decreases the permeability of rocks Generally cement grout is used Water retaining structures like dams, it is used to reduce seepage Intrusion Grouting INTRUSION GROUTING

8. COMPACTION GROUTING (DISPLACEMENT GROUTING) Grout is inserted with pump at high pressure to form a series of intrusions in deposit 25 mm thick slump doesn’t penetrate deep in soil and compact the adjacent soil Resulting increase in strength Generally used in loose soil as well as unsaturated fine-soil When to restore the structure having excessive settlement, compaction grouting is used to reduce the settlement Compaction Grouting

9. PERMEATION GROUTING Permeation Grouting Thin grouting is inserted into soil that permeates into voids of soil The grout cures after a time and turns the soil into solid mass Generally used in fine-grained soil Makes the soil less compressible , strong and impermeable Applied to the projects of tunneling and stabilizing soil before excavation

10. Pipe fitted with horizontal jets inserted into soil at require depth and with pressure grout is inserted Pipe is gradually raised and rotated while grouting still being injected Column is formed in the soil that makes the soil impermeable and strong Applied to water-logged area as well as in stabilization of soil before excavation and tunneling operations JET GROUTING

11. Compensation Grouting is a process used to control or reverse the settlement of structures It consists of the injection of material into the soil between the foundation to be controlled settlement The material injected is forced into fractures thereby causing an expansion to take place counteracting the settlement that occurs or producing a controlled heave of the foundation Because the process requires that the soil is fractured and not permeated, Compensation Grouting may be used in most soil types ranging from gravels to clays or weak soils COMPENSATION GROUTING

12. Preventing flow either through the sides or into the base of an excavation Preventing or reducing contamination f l o w through the ground Controlling groundwater during tunneling Preventing or reducing water seepage through a water retention structure such as a dam or flood defense structure Ground Water Control

13. * Effective in a variety of soil conditions *Wide applications range * Speed of installation *No need to connect to footing or column

14. General Applications of Grouting Seepage Control

15. Soil Solidification and Stabilization

16. Thanks a lot for your kind listening and attention