Choosing a Ground Improvement Technology · GHRM Chapter 17

← Chapter 17 — Ground Improvement Methods · 17.16

Section 17.16 · Selection guide

Choosing a technology for a railway problem

Find the problem on the cross-section, read the section that explains the method, then open the technology sheets to compare options.

8Railway problems

35Technology sheets

1Locate the problem on the section

2Read the method in the chapter

3Compare the technology sheets

1

Soft clay under embankment

Soft, compressible clay under new or widened embankment

Drain, preload or support on columns

Read first

17.3 PVDs & preloading 17.4 Stone columns 17.5 Deep soil mixing

Technology sheets 6

17.16.36Prefabricated Vertical Drains and Fill Preloading 17.16.43Vacuum Preloading with and without Prefabricated Vertical Drains 17.16.8Column-Supported Embankments 17.16.9Combined Soil Stabilization with Vertical Columns 17.16.13Deep Mixing Methods 17.16.26Geotextile Encased Columns

2

Loose sand or silty sand

Loose sand or silty sand — settlement or liquefaction

Densify or replace with columns

Read first

17.2 Densification 17.4 Stone columns

Technology sheets 6

17.16.45Vibrocompaction 17.16.12Deep Dynamic Compaction 17.16.37Rapid Impact Compaction 17.16.4Blasting Densification 17.16.1Aggregate Columns 17.16.38Sand Compaction Piles

3

Weak or pumping subgrade

Weak or pumping subgrade under track, yard or access road

Stabilize, separate and reinforce

Read first

17.7 Lime & cement 17.8 Geosynthetics

Technology sheets 6

17.16.7Chemical Stabilization of Subgrades and Bases 17.16.31Mechanical Stabilization of Subgrades and Bases 17.16.2Bio-Treatment for Subgrade Stabilization 17.16.16Excavation and Replacement 17.16.21Geosynthetic Reinforced Embankments 17.16.23Geosynthetic Separation in Pavement Systems

4

Voids, sinkholes, lost backfill

Voids, sinkholes, abandoned mines or culvert backfill loss

Fill and densify by grouting

Read first

Technology sheets 4

17.16.10Compaction Grouting 17.16.5Bulk-Infill Grouting 17.16.6Chemical Grouting & Injection Systems 17.16.30Jet Grouting

5

Cut or embankment slope instability

Nail, retain or reinforce

Read first

Ch 13 Slope stability Ch 16 Retaining structures

Technology sheets 6

17.16.14Drilled-Grouted and Hollow Bar Soil Nailing 17.16.39Screw-in Soil Nailing 17.16.40Shoot-in Soil Nailing 17.16.32Mechanically Stabilized Earth Wall System 17.16.41Shored Mechanically Stabilized Earth Wall System 17.16.1Aggregate Columns

6

Foundations near live track

Foundations near live track / limited headroom

Small-footprint deep foundations

Read first

Ch 11 Bearing capacity

Technology sheets 4

17.16.33Micropiles 17.16.27Helical Pile 17.16.11Continuous Flight Auger Piles 17.16.30Jet Grouting

7

Compaction QA & fill acceptance

Compact and verify

Read first

17.2 Compaction Ch 15 Monitoring

Technology sheets 3

17.16.29Intelligent Compaction 17.16.42Traditional Compaction 17.16.28High-Energy Impact Rollers

8

Reuse of on-site or recycled materials

Reuse instead of import

Read first

17.7 Stabilization

Technology sheets 3

17.16.3Beneficial Reuse of Waste Materials 17.16.34Onsite Use of Recycled Pavement Materials 17.16.16Excavation and Replacement

Click a number on the cross-section to jump to its card. Some technologies, such as aggregate columns, jet grouting, and excavation and replacement, serve more than one problem. Technology sheets open on dirtbert.com.