The document discusses erosion issues along the Bârlad River in Vaslui, Romania. It describes heavy erosion on both sides of a bridge, threatening its pillars. It proposes the following solutions: 1) Redirecting the river flow through a new channel on the left bank to stop erosion on the right bank. 2) Consolidating eroded riverbanks with wooden pilings and planting vegetation to stabilize the soil. 3) Using wooden gabions and cables to stabilize a pillar threatened by erosion on the right bank upstream of the bridge.

1. Bârlad River in the industrial area of Vaslui
The first method
Ph.D Razvan Voicu
rzvnvoicu@yahoo.com, getiiliberi@gmail.com,
Bârlad River, in the industrial area of Vaslui, is heavily eroded. This erosion is
found on both sides of the bridge (fig.1) traversed by cars and trains connecting the cities
Bacău and Vaslui. Due to large dike (fig.2) built inside river, the water by-passes it and
heavily erodes the right bank of the river. The right bank is eroded about 10 meters
downstream from the dike (fig.3).
bridge
Bârlad River
Figure 1 Bridge on the industrial area of Vaslui
right bank erosion
dike
Figure 2 Dike built inside Bârlad River bed

2. left bank erosion
right bank erosion
Figure 3 Bârlad River, downstream from the bridge
Heavy erosion is threatening the stability of pillars (fig.4) upstream of bridge, which
support the gas pipeline.
gas pipeline
Bârlad River
Figura 4 Gas pipeline crossing the Bârlad River

3. For ecotehnical redevelopment of Bârlad River regarding 100 meters in the
immediate vicinity of the bridge, the following works are to be performed downstream
from the bridge:
- Complete redirectioning of Bârlad River waters through a channel built in the left
bank;
- Consolidation of river banks using wooden sheet-piling for the two heavily
eroded areas;
- Linearization of both river banks for approximately one hundred meters
downstream from the bridge;
- Backfilling of any spaces in the banks throughout the length of the study section;
- Developing inclined banks in order to support the root system of plants meant to
hold up the banks.
Complete redirectioning of Bârlad River waters through a channel built in the left
bank;
Stopping erosion, which may extend up to dikes jeopardizing the road and railway
line, also the two roads near the banks, should be considered. Any major construction
of watercourses ecological restoration is achieved by redirecting water from the
channel selected as study. Redirecting water will be immediately performed behind
the wastewater pipeline located across the water course (fig.5)
wastewater pipeline
Bârlad River
Figure 5 Redirecting water system

4. Barlad River water will be redirected by the means of a metal sheet-pile equipped
with supporters and anchorage system fixed in the river bank. (fig.5).
The water redirecting channel (Fig. 5) is rectangular and should entirely capture
the Bârlad river waters. The rectangular channel will be located on the left bank, at
almost five meters from the edge of major erosion on the left bank and lead its waters
towards the Bârlad riverbed, at about 100 meters from the bridge.(fig. 6).
road channel arable land
dike
Bârlad River
heavy
erosion
Figure 6 Rectangular channel construction for taking the Bârlad River waters

5. road channel arable land
redi recting water system
dike
heavy
erosion
Figure 7 Redirecting water system, rectangular channel functionality for collecting the
Bârlad river water on the established sector
In Figure 7, by redirecting the watercourse, the riverbed sector is ready for the
ecotehnical method presented.

6. Consolidation of river banks using wooden sheet-piling for the two heavily eroded
areas
Before compacting with soil, heavily eroded areas from the study sector should be
reinforced with wood sheet-piling fig 8. The sheet-piling are fixed into the slopes by the
means of some wooden plates. Both the plates and sheet-piling are fixed into the slopes
by the means of some plastic dowels provided with stoppers.
sheet-piling
plates supporting the sheet-pil ing dowels
Figure 8 Banks consolidation using wood sheet-piling
After setting all sheet-piling in the eroded areas, the water flow sector is smoothed
so as to form a rectangular channel able to support the riparian vegetation to be planted.
Banks will be arranged on inclined plane; various fast-growing woody species
(alder, willow) and herbaceous species with fasciculated roots (sedge, fescue, etc.) will be
planted in line or diamond along the banks). For example, figures (Fig. 9) and (Fig. 10)
show the success of ecotehnical methods applied to various river banks.

7. a) during ecotehnical works b) after completion of ecotehnical works,
Figures (9 si 10) Ecotehnical arrangement of a river – UK
(Source: http://www.salixrw.com)
By the time the development of vegetation is completed, the area will have been
surrounded by a protective fence. These bioengineering methods are often used in
developed countries, successfully replacing the old classic engineering methods which
altered the ecological watercourses.

8. road channel arable land
redirecting water system
Figure 11 Ecotehnical measures completed for Bârlad River

9. After completion the ecotehnical works of banks consolidation, including
destruction of deck, the rectangular channel drawing all water off from the Bârlad River
can be destroyed, or can be used as side channel connectivity for the Bârlad River
waters. After the ecotehnical arrangement, the water redirecting system will be designed
to redirect up to 25% of Bârlad waters through the rectangular channel. If the channel
through which Bârlad River waters were redirected remains functional, then this channel
will be less deep and provided with other link channels in order to ensure an effective
connectivity.
The second method
There is some erosion on the other side of the bridge and it endangers a pillar
supporting the gas pipeline fig. 12.
gabion gas pipeline
Bârlad River
Figura 12 Erosion of the right bank of the Bârlad River, upstream of the bridge
Bank erosion can be stopped using wooden gabions filled with pressed rolls made
of coconut fibers or layers of fascines. The gabion will be bent and fixed in some beams
of wood which, in turn, are deeply attached to the ground. At the middle, the pillar must
be fitted with two cables, also attached to the ground fig.13.

10. gas pipeline
pillar supporting the pipe
supporting cable
Bârlad
River
wattle wooden elastic gabion
Figure 13 Stabilizing the bank of the Bârlad River
The arched gabion is a powerful system made to support the soil, both by its
structure but also by its pushing force. Also, a wattle fence for sustaining the river banks
is built. All these ideas can be implemented with greater chance of success.
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Bucharest
2011