This document provides guidance on maintenance of structures under the Pradhan Mantri Gram Sadak Yojana (PMGSY) rural roads program. It discusses the types of structures commonly built for PMGSY roads like drains, culverts, causeways and bridges. It emphasizes the importance of regular inspection and maintenance to ensure structures function properly and prevent water damage. The document then provides detailed checklists and guidance on inspecting and addressing common defects for each type of structure, such as blockages, erosion, cracks and settlement. References for further information are also included.

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Maintenance of various
structures comes under
PMGSY Roads
By
Er. I.M. Siddiqui
DCE (Hons), B.E. (Civil), LLB, M.E. (W.R.), MBA.
MIE (India), CE, LM,WRS, LM IRC, LM I0V MICA
Ex. Project Director . NHAI
GM, MPRRDA , PIU-Kukshi (Dhar-2)
Email ID :- imswrd@yahoo.co.in

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Preamble
I would like to emphasize to adopt
following priorities to construct
maintenance free roads:
(i) Provide adequate drainage.
(ii) Provide adequate drainage.
(iii) Provide adequate drainage.

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1. Types of structures: Normally
following structures are built
in PMGSY roads:
i. Drains
ii. Hume Pipe Culverts
iii.Cause ways
iv.R.C.C. Slab Culvert or
Box Culvert or Bridges

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Function of all the above
structures to drain surface water
freely and quickly away from the
road or under the road. Water
worst enemy of any road. It can
erode soils, weaken pavements &
sub grade, destroy shoulders and
slopes, wash out road pavement
& sub grade, culverts and even
bridges.
2. Function:

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i. Before onset of monsoon.
ii. During monsoon particularly first
flash floods.
iii. After heavy floods.
iv. After monsoon.
3.Inspection:
Inspection of drainage system and
structures shall be a routine task. If it
is not possible then the inspections
should be carried out at least on
following four occasions:

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(i) Inspection before onset of
monsoon:
Following points shall be inspected:
a) Water way is clear and not blocked by debris or silt.
b) Settlement cracks in foundations or in super
structures.
c) Cracks or damage in pavement.
d) Guard stones are properly fixed & painted.
e) Warning signs are placed on both sides of cross-
drainage structures.
f) Approaches are in sound condition and there is no
erosion.
g) Debris arrestors if provided is properly fixed.

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(ii) Inspection after first flash flood:
It is generally observed that during first
flash flood or during next two, three spells,
there is substantial load of floating debris
along the flood water. If the vents are not of
sufficient opening, then waterway is blocked
by the debris and water starts flowing on
approaches or by breaching the adjoining road
sections. It is therefore, essential to remove
this blocked debris from pipe vents or
waterway immediately so that there will be
minimum damages in subsequent floods. In
view of this, close and repeated inspections
are essential during rainy season.

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During heavy flood, causeways are
generally over topped. This results in
heavy damages to pavement,
approaches as well as scouring on down
stream side of structures. In some cases
there is breaching of approaches. All
these points shall be closely inspected
after every flood, so that timely
protective measures can be taken.
(iii) Inspection after heavy flood:

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(iv) Inspection after monsoon:
Once the monsoon season is
over, the structure shall be
inspected closely for any damage,
any heavy silting or scouring to
pavement, damages to guide stones
etc. repairs to these damages shall
be carried out properly.

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4. Inspection Check List
i. Drains : Defects observed
a)Drain Cross Section destroyed
b)Pounding in drain.
c) Silting
d)Erosion

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Causes & Remedy
(a) Drain Cross Section Destroyed:
Causes : Blockage by debris and
vegetation, if neglected
cross section is reduced
and can not flow as
intended resulting
overflow and damage to
road.
Remedy : Cleaning, Clearing
Repairing

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(b) Ponding:
Causes : Cross section too small,
gradient improper etc.
causes ponding resulting
the softening of shoulder
material and it erose easily.
The pavement & sub grade
can also be flooded and thus
weakend.
Remedy : Redesign the drain to
carry the required
discharge and improve
the size & gradient.

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(c) Silting:
Causes : Invert slope is too flat, water
can not flow at sufficient
velocity, presence of
vegetation etc. starts
deposition if neglected drain
will get blocked and results
overflow caused damage to
road.
Remedy: Redesign the drain for
non silting velocity,
remove vegetation, provide
lateral drains etc.

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(d) Erosion:
Invert and sides of drains are croded
Causes : Invert Slope is too steep. If
neglected, water flows at too
high a velocity and starts
carrying away the soil, the
drain becomes deeper. The
sides then cave in, the
shoulder can even part of
carriageway can be washed
away.
Remedy : Lining/Pitching drain slopes and
invert, regarding, realigning,
redesign.

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(ii) Hume Pipe Culverts:
Defects :
(a) Silting, Sanding, Blockage of debris.
(b) Erosion of stream bed at culvert .
(c) Settlement cracks.
(d) Cracks in middle of head walls.
(e) Settlement in riding surface in pipe
portion.
(f) Flow through junction of underneath
of invert of pipe and headwall.
(g) Tilting of Headwall.

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(a) Silting, Sanding, Blockage of debris:
Cause:
Invert slope too flat, culvert constructed
too low, so that material from stream bed
gets deposited in the pipes. Vegetation
and flooding debris carried by water
blocks the vents of culverts. If neglected,
the intended water way opening will be
so reduced that flood water can not flow.
It will backup the pond on the U/s of
culvert and may eventually overflow the
road embankment. The road is in danger
of being washed away.

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(a) Silting, Sanding, Blockage of debris:
Remedy:
Cleaning and clearing. If flooding
debris is a problem, the provision of
debris rack should be considered.
Slopes of the bed shall be corrected by
nala training properly.

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(b) Erosion of stream bed at culvert
out let:
Cause:
Due to flowing water or overtopping of water
from culvert, the D/s bed some times gets
eroded. Due to heavy scouring, the
foundations of head walls are also exposed
and endangered. Due to steep slope of bed
or vents or due to inadequate waterway, the
velocity of flowing of water increases on D/s
and results in erosion below headwall, wing
walls or even approaches. This may result in
collapse of head wall or wing walls in due
course of time.

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(b) Erosion of stream bed at culvert
out let:
Remedy:
Protection work to the bed with
properly designed apron at D/S
shall be provided. Adequate water
way shall be provided.

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(c) Settlement Cracks:
Cause:
Settlement of foundations takes place due to
weak foundation strata.
Remedy:
If the settlement is negligible then the
damages can be checked and repaired. But,
if the settlement is major in nature then the
settlement is major in nature, then
reconstruction of structure will only be the
remedial measure.

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(d) Cracks in middle of head walls:
Cause:
Probable cause of these cracks are
insufficient earth cushion over
Hume pipe. The traffic load causes
impact on pipes and the stresses
transmits to head wall, resulting
cracks.

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(d) Cracks in middle of head walls:
Remedy:
Minor cracks hardly affect the
functioning of structures, these
should be repaired by rich cement
mortar. However if cracks are
major, apart from to repair it, also
provide proper earth cushion or
encase the Hume pipe by M15 C.C.
or provide C.C. pavement above the
Hume pipes.

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(e) Settlement in riding surface in
pipe portion:
Cause:
Either quality of backfill material is poor
or compaction poor or the combination of
both. The entrance of water through
joints of pipes may also lead this
problem.
Remedy:
Remove the backfill material and refill
with good quality material in layers of 15
cm thick duly rammed & watered. Seal the
joints of pipes with jute and rich cement
mortar.

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(f) Flow through junction of
underneath of pipe & head wall:
Cause:
Formation of cavity between around
the periphery of pipe and C.C. of
head wall.
Remedy:
Fill the cavity with rich cement
mortar.

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(g) Tilting of headwalls:
Cause:
Faulty design of section of headwall.
Remedy:
Reconstruct the headwall giving due
consideration to backfill.

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(iii) Cause Ways:
The surface of causeways is
endangered by water current
Routine maintenance in this case
can only be regarded as temporary
measures. Remedy include concrete
repair, placing of stone crates and
erosion protection.

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Inspection Checklist: Defects
observed
(a)Cracks in paved surface.
(b)Blockage of vents due to debris.
(c)Damage to guide stone,
information boards.
(d)Over flanking during overtopping
of water & erosion of D/S bed.
(e)Washout of top slab.

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(a) Cracks in paved surface:
Cause:
Settlement of slab, if neglected, the
cracks in concrete slab spread and
widen especially during the following
flood season.
Remedy:
Minor surface repair i.e. sealing the
cracks.

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(B) Blockage of vents due to
debris :
Cause:
Floating debris blocks the vents.
Remedy:
Debris arrestors shall be provided on
U/S side or make sure timely
cleaning of debris during monsoon
period.

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(c) Damage to guide stone,
information boards :
Cause:
Due to flood water, or due to
vandalism such damages are
experienced. If neglected, when
pavement gets submerged during
floods, the edge of pavement can not
seen, more over if guide stones are
missing, the depth of watch or road
top level can not be judged. This may
result serious accidents.

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(c) Damage to guide stone,
information boards :
Remedy:
Debris arrestors shall be provided on
U/S side or make sure timely cleaning
of debris during monsoon period.

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(d) Over flanking during overtopping
of water & erosion of D/S bed :
Cause:
If structure is not properly designed
or provision of inadequate water way
or inadequate protection measures.
Causes over flanking during
overtopping and erosion of D/S bed.

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(d) Over flanking during overtopping
of water & erosion of D/S bed :
Remedy:
The geometry of the structure shall be
properly designed. Water way shall be
provided in such a way that it shall
effectively pass at least 20% of high
flood discharge. The Road top level
shall be properly protected with
pitching on U/S and D/S as well as top
formation extending up to H.F.L. If
possible RCC wearing coats must be
provided.

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(e) Washout of top slab :
Cause:
If slab is laid over head walls during
overtopping it may washout.
Remedy:
The slab should be laid between head
walls not top of head walls. The
anchoring of edges of slab in U/S &
D/S is also suggested if slab is laid
over headwalls.

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(iv) RCC Sub culverts, Box Culvert or
Bridges:
Defects commonly observed:
(a)Non Function of Weep holes and
settlement of approaches.
(b)Blockage of vents.
(c)Erosion in near by piers or abutments
or D/S apron & approaches.
(d)Missing of Sign Boards.
(e)Loosening of concrete cover and
corrosion in reinforcement.
(f) Washout of slab.

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(a) Non Function of Weep holes
and settlement of approaches :
Cause:
Chocking of weep holes cause
accumulation of water behind the
abutments & retaining walls
resulted settlement in approaches.
Remedy:
Remove the fill and clean the weep
holes and make inverted filter
behind it. Then refill the approaches
in layers with good quality material
duly rammed & watered.

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(b) Blockage of Vents:
Cause:
Floating debris may cause blockage.
Remedy:
Clear & clean the blockage.

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(c) Erosion:
Cause:
Heavy floods may cause erosion.
Remedy:
Provide proper protection works
either by stone crates or by
concrete blocks

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(d) Missing of Sign Boards:
Cause:
Vandalism.
Remedy:
Replace the same.

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(e) Loosening of Concrete Cover &
Corrosion in reinforcement:
Cause:
Due to weathering effect, the
corrosion took place in the
reinforcement resulting loosening of
concrete cover. This may reduce the
life of structure
Remedy:
Epoxy resin compound should be
used for anticorrosive coating for
reinforcing steel. The application
should be as per instruction of
manufacturer.

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(f) Wash out of slab:
Cause:
In submersible bridges if anchorage
is not made with piers & abutment or
stoppers are not provided, the slab
may wash out during flood.
Remedy:
Provide stoppers or anchorage the
slab .

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References:
(a) Manual for maintenance of roads
IRC publications
(b) S.P. 20- Rural road manual IRC
publication
(c) Pocket book for bridge Engineers
published by MOST.

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Thanks
I.M. Siddiqui
G.M., MPRRDA, PIU, Kukshi
(Dhar-2)