Environmental Engineering Reference
In-Depth Information
Atlantic city, NJ
(tidal marsh behind
barrier beach)
Atlantic city, NJ
(barrier beach)
Flushing meadows,
flushing, NY
(filled tidal marsh)
Depth
mft
N
N
N
Black peat
Gray fibours organic
silt with
shells
Gray organic silt
and sand with
layers of fibrous
organic silt and
shells
12
Gray silty fine
sand
Miscellaneous fill
sand, cinders,
wood
10
0
35
5
83
10
5
67
2
loose
4
−
5
1
LL = 88
PI = 48
w
n
= 62
20
68
87
2
24
Gray silty sand,
gravelly with
occasional
shells
Gray silty
gravelly sand
30
49
Peat
187
30
Brown silty sandy
clay
15
10
2
Gray organic silt
Dark gray organic silt
Gray gravelly sand
Gray sandy clayey silt
Gray silty sand
10
96
30
53
70
Gray silty
gravelly sand
1
40
34
1
100
50
15
120
2
60
2
80
6
Peat
Legend: N = Standard penetration test value
=Ground water table
LL = Liquid limit (%)
25
19
Gray
gravelly
sand
PI = Plasticity index
w
n
= Natural water content (%)
90
20
Peat
15
Brown silt with
clay and sand lenses to 200 ft
30
100
FIGURE 7.47
Logs of test borings representative of conditions of a subserial depositional coast. (Courtesy of Joseph S. Ward
and Associates.)
coastlines can be extremely variable and include weak soils interbedded with strong. The
buried soft organic soils can be expected to be very irregular in thickness and lateral dis-
tribution, and careful exploration is required to identify their presence. If not accounted
for in design, significant differential settlements of foundations result.
Emerged Depositional Coast
The significant features of emerged depositional coastlines are a series of wave-
cut terraces or beach ridges, as illustrated in
Figure 7.48,
on which tidal lagoons are also
