Shoring Evaluation Matrix
No.
1
2
3
4
5
Shoring Type
Section in
Drawing
Configuration
Importance Scale: 1 = Low, 2 = Medium, 3 = High
Contiguous piles with tie‐back Section A‐A, About 60 – 70 cm contiguous
piles separated 5cm at their
anchors
Approach‐
edges. The piles are
01
embedded into the soil below
the excavation level and
supported by one line of tie‐
back anchors.
Contiguous piles without tie‐
Section A‐A, About 70 – 80 cm contiguous
piles separated 5cm at their
back anchors – Cantilever type Approach‐
edges. The piles are
02
embedded in the soil below
the excavation level and
acting as cantilever.
Solider piles
Section A‐A, Steel H sections at 2.0 – 2.5 m
with tie‐back‐anchor at the
Approach‐
top of the piles to support RC
03
panels.
Soil nails
Braced system
Advantages
‐ Less pile diameter and
embedded length into
the soil than type No.
2.
‐ No work outside the
property limit.
‐ Temporary shoring
could be reused
Section A‐A,
Approach‐
04
Soil nails are inserted into an
inclined surface of the
retained soil.
Shotcrete and wire mesh are
applied to the surface of the
slope for protection.
‐ Relatively low cost
Section B‐B
Internal bracing is used rather
than the tie‐back‐anchors to
provide lateral support for the
shoring.
‐ Less pile diameter and
embedded length in
the soil than type No.
2.
‐ No work outside the
property limit
Note: Lowest: Mark = 1, Highest: Mark = 10
Total Mark = Σ Importance scale * Mark
‐The figures set forth on the above Table shall be checked and confirmed by the shoring contractor.
Disadvantages
‐ Needs authority
approval for the
extension of tie‐back
anchors outside the
property limit.
‐ Relatively long time of
construction
‐ More material cost
‐ Needs authority
approval for the
extension of tie‐back
anchors outside the
property limit
‐ Takes long construction
time.
‐ Needs authority
approval for the
extension of the nails.
‐ Takes long construction
time
‐ Not extensively used in
the market
‐ Adjacent structure
should be flexible.
‐ Bracing Impede
somewhat the
excavation.
‐ Needs 2 sides (parallel
or inclined) facing each
other to provide the
stability
Special
conditions
2
Issuing
approval
from
authority
3
6
6
4
9
105
9
8
8
10
9
130
9
5
7
4
4
5
93
9
5
3
4
4
4
78
9
7
8
7
10
10
139
Mater
ial
cost
Construc
tability
Extensive
use in the
market
Construc
tion time
3
2
3
8
6
5
Total
Marks
3