Table 2
Port Bolivar Dike
Port Bolivar, Texas
,
Construction and Rehabilitation History
A 1,700-ft-long steel sheet-pile dike was constructed to prevent
shoaling in the Gulf Intracoastal Waterway at this location (Fig-
1934
ure 3 . The seaward end of the dike consisted of a 12-ft-diam sheet-
)
pile cell, with a 2-ft-thick concrete cap (and underlying fill
material), protected by a stone blanket at the toe of the cell. The
top elevation of the sheet pile was
Existing water depths
(landward) to -13 (seaward) ft mlt. A total of 47,500
varied from
sq ft of sheet pile and 6,670 tons of stone was used. Cost of the
improvements was ,000.
The landward end of the dike was repaired and extended 200 ft at a
cost of ,050. Approximately 230 tons of stone was placed as scour
1937
protection at the seaward end at a cost of
||content||
,750.
The outer 1,230
of sheet pile was supplemented with a rubble-
mound section similar to the 1964-1965 Port O'Connor repairs. The
dike was generally intact, with some damage to the piling at the
outer end and a heavy coating of rust scale due to saltwater ex-
posure. Existing ground elevations varied from -5 ft mlt near the
seaward end to
ft mlt along the unrepaired landward segment
general, an accretion of 6 to 8 ft had occurred since original
construction). The outer sheet-pile cell, with a maximum water depth
of - 1 1 ft
was the only section where localized scour was evident
(but in this case not critical to structural integrity). The sheet-
pile top elevation was generally from
to
(within
0.5 ft of the design elevation). The rubble-mound design sections
(Figure 3, inset), with the existing dike at the center line, had a
(seaward) to
(landward) ft mlt, a
crown elevation varying from
crown width of approximately 8 ft (2 cover stones wide) and
side slopes. The sections were built upon a 2-ft-thick (3 ft at
outer end) bedding layer of 0.5-in. to 200-lb stone. The bedding
layer extended from 3
(landward) to 1 ft (seaward) beyond the toe
0
of the cover layer and was covered with a 2-ft-thick layer of 200- to
1,000-lb apron stone. Similar sized stone were used as core stone,
and the outer layer consisted of 1- to 6-ton stone.
stone
to 4 in.) also were placed with the core stone, in a section
side slopes. The general pur-
extending beneath the crown at
pose of filler stone is to decrease permeability and reduce sediment
transport through the structure. The cover stone size was selected
based partly on Hudson's slope stability equation and partly for
economic reasons. A total of 19,280 tons of stone was placed at a
cost of 4,700.
The dike presently is considered to be in good condition.
1985
15
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