<p>I am currently working at the Tren Maya project in México as part of the planing department; anyways I studied a Masters degree, and looking at the executive project, there are some parameters I’ve looked around a lot in the literature and I find myself unable to find the why of them, and I’m just curious about.</p>
<p>My question is simple, in the design of the railway embankment, lets say we have a 7 meters height embankment over a natural soil that meets the loading capacity, so it is divided in layers of 0.3 meters such that the bottom n layers must meet a 90% compaction degree, and the last 5 upper layers must meet a ≥ 97% compaction degree. Searching I found out in &quot;Geotechnical Parameters of Soil, Considering the Effect of Additional Compaction of Embankment&quot; that the reason why is that upper layer compaction actions indirectly compact lower ones, and this effect must be considered in the design.</p>
<p>Yet, generally this compaction degree seem to default to be greater than 90% for lower layers and greater than 97% or 100% for upper layers. A prove of this:</p>
<p><a href="https://i.sstatic.net/UiGNR.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/UiGNR.png" alt="Capture from Technical memorandum of the California H-S Train Project" /></a></p>
<p>Why 90%? Why not 91% of compaction degree? Or 92%? or 100%? I know compacting all layers 100% degrees would be pretty high in costs, but then why 90%?</p>

CC BY-SA 4.0
2022-06-03T05:59:11.433Z
This question is asking about the soil compaction regime for a railway embankment. Such environments are engineered to support a railway line. This question might be more appropriate on SE Engineering.
Fred
CC BY-SA 4.0
2022-06-03T12:02:36.787Z
I will change it then, I asked here because I just see a post about Embankments. Thanks for all.
ecoli404
<soil><research>
How is layer compaction degree designed to be ≥90% in lower layers and ≥ 95% in the upper 5 ft in a railway embankment?
ecoli404
# How is layer compaction degree designed to be ≥90% in lower layers and ≥ 95% in the upper 5 ft in a railway embankment?

(Asked by: username_0 on 2022-06-02)

I am currently working at the Tren Maya project in México as part of the planing department; anyways I studied a Masters degree, and looking at the executive project, there are some parameters I’ve looked around a lot in the literature and I find myself unable to find the why of them, and I’m just curious about.

My question is simple, in the design of the railway embankment, lets say we have a 7 meters height embankment over a natural soil that meets the loading capacity, so it is divided in layers of 0.3 meters such that the bottom n layers must meet a 90% compaction degree, and the last 5 upper layers must meet a ≥ 97% compaction degree. Searching I found out in "Geotechnical Parameters of Soil, Considering the Effect of Additional Compaction of Embankment" that the reason why is that upper layer compaction actions indirectly compact lower ones, and this effect must be considered in the design.

Yet, generally this compaction degree seem to default to be greater than 90% for lower layers and greater than 97% or 100% for upper layers. A prove of this:

[![Capture from Technical memorandum of the California H-S Train Project](https://i.sstatic.net/UiGNR.png)](https://i.sstatic.net/UiGNR.png)

Why 90%? Why not 91% of compaction degree? Or 92%? or 100%? I know compacting all layers 100% degrees would be pretty high in costs, but then why 90%?

**Tags:** soil, research

> **Comments:**
> **username_1**: This question is asking about the soil compaction regime for a railway embankment. Such environments are engineered to support a railway line. This question might be more appropriate on SE Engineering.  
> **username_0**: I will change it then, I asked here because I just see a post about Embankments. Thanks for all.  

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## 0 answers

