← 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
Railway cross-section showing where each of the eight ground problems occurs Soft clayLoose sandBedrock Cut slopeStockpileEmbankment fill 1234 5678
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 & preloading17.4 Stone columns17.5 Deep soil mixing
Technology sheets 6
17.16.36Prefabricated Vertical Drains and Fill Preloading17.16.43Vacuum Preloading with and without Prefabricated Vertical Drains17.16.8Column-Supported Embankments17.16.9Combined Soil Stabilization with Vertical Columns17.16.13Deep Mixing Methods17.16.26Geotextile 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 Densification17.4 Stone columns
Technology sheets 6
17.16.45Vibrocompaction17.16.12Deep Dynamic Compaction17.16.37Rapid Impact Compaction17.16.4Blasting Densification17.16.1Aggregate Columns17.16.38Sand 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 & cement17.8 Geosynthetics
Technology sheets 6
17.16.7Chemical Stabilization of Subgrades and Bases17.16.31Mechanical Stabilization of Subgrades and Bases17.16.2Bio-Treatment for Subgrade Stabilization17.16.16Excavation and Replacement17.16.21Geosynthetic Reinforced Embankments17.16.23Geosynthetic Separation in Pavement Systems
4
Voids, sinkholes, lost backfill

Voids, sinkholes, abandoned mines or culvert backfill loss

Fill and densify by grouting
Read first
17.6 Grouting
Technology sheets 4
17.16.10Compaction Grouting17.16.5Bulk-Infill Grouting17.16.6Chemical Grouting & Injection Systems17.16.30Jet Grouting
5
Cut or embankment slope instability
Nail, retain or reinforce
Read first
Ch 13 Slope stabilityCh 16 Retaining structures
Technology sheets 6
17.16.14Drilled-Grouted and Hollow Bar Soil Nailing17.16.39Screw-in Soil Nailing17.16.40Shoot-in Soil Nailing17.16.32Mechanically Stabilized Earth Wall System17.16.41Shored Mechanically Stabilized Earth Wall System17.16.1Aggregate 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
17.16.33Micropiles17.16.27Helical Pile17.16.11Continuous Flight Auger Piles17.16.30Jet Grouting
7
Compaction QA & fill acceptance
Compact and verify
Read first
17.2 CompactionCh 15 Monitoring
Technology sheets 3
17.16.29Intelligent Compaction17.16.42Traditional Compaction17.16.28High-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 Materials17.16.34Onsite Use of Recycled Pavement Materials17.16.16Excavation 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.