soil nailing
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A
Seminar Report
On
Soil NailingBy
More Abhijit AshokUnder the guidance of
Prof. R. R. SorateSubmitted in partial fulfilment of the requirement for
T. E. (Civil Engineering)
2014-2015
Savitribai Phule Pune University
Department of Civil Engineering
Sinhgad Technical Education Society’s
Sinhgad Academy of Engineering, Kondhwa, Pune-411048
Soil Nailing 2014-15
Sinhgad Technical Education Society’s
Sinhgad Academy of Engineering, Kondhwa, Pune
Certificate
This is to certify that More Abhijit Ashok, Examination No T120430086 of TE (Civil Engg.)
has submitted his Seminar Report on “Soil Nailing ” under the guidance of Prof. R. R. Sorate
towards the partial fulfillment of the requirement for T.E.(Civil Engineering), Savitribai Phule
Pune University for the Academic year 2014-15.
Prof. R. R. Sorate External Examiner
(Seminar Guide)
Prof. R. B. Bajare (HOD) Prof. A. Dhananjay
Department of Civil Engineering (Seminar Co-ordinator)
Dr. Vijay N. Wadhai
Principal
SINHGAD ACADEMY OF ENGINEERING, PUNE-48 Page 2
Soil Nailing 2014-15 SAOE, Pune.
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ACKNOWLEDGEMENTI would like to take this opportunity to express my honour, respect, deep gratitude
and genuine regards to my seminar guide PROF. R. R. SORATE for giving me all guidance required for my seminar entitled “SOIL NAILING” apart from being a constant source of inspiration and motivation. It was indeed my privilege to have work under him. I am also extremely grateful to staff member of CIVIL ENGINEERING DEPARTMENT for their constant encouragement and kind help during my seminar for providing all facility & help for smooth progress of seminar work.
Last but not least, the backbone of my success & confidence lies solely on blessings of my parents & my friends.
Thanking You,Date: / / 2015
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ABSTRACT
Since its development in Europe in the early 1970s, soil nailing has become a widely
accepted method of providing temporary and permanent earth support, underpinning
and slope stabilization on many projects in the United States. In the early years, soil
nailing was typically performed only on projects where specialty geotechnical contractors
offered it as an alternate to other, conventional systems. More recently, soil nailing has
been specified as the system of choice due to its overall acceptance and effectiveness.
However, although the theoretical engineering aspects of soil nailing may be well
understood, there is a far lesser degree of understanding, even within the geotechnical
community, as to the site conditions – where, when and why – under which soil nailing
should, and should not, be used. The purpose of our seminar, therefore, is to study the
technique to decide if soil nailing is the right system for engineering projects or not.
Typical soil nail details, procedures, design, monitoring and testing considerations and
case studies are presented as a tool to aid in making those decisions.
Soil nailing is an in-situ reinforcement technique by passive bars which can
withstand tensile forces, shearing forces and bending moments. This technique is used
for retaining walls and for slope stabilization. Its behavior is typical of that of composite
materials and involves essentially two interaction mechanisms: The soil- reinforcement
friction and the normal earth pressure on the reinforcement. The mobilization of the
lateral friction requires frictional properties for the soil, while the mobilization of the
normal earth pressure requires a relative rigidity of the inclusions. Taking into account
these mechanisms, multi-criteria at failure design method is proposed. It is derived from
the slice methods used in slope stability analysis. The criteria lead to a yielding curve in
the shear – tensile forces plane and the consideration of the principle of the maximum
plastic work enables to calculate the shear and tensile forces mobilized at failure in each
inclusion. Using formulation determinate, the slope stability analysis takes into account
the passive force of reinforcement.
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CHAPTER-1
INTRODUCTION
The slope stabilization method of soil nailing is used to reinforce the existing
ground by installing threaded steel bars into the slope or cut wall as construction
proceeds from the top down. Soil nails are installed to create a stable mass of soil. This
process creates a single block of earth that is stable and able to hold back the soil behind
it. Soil nailing is an economical means of constructing shoring systems and retaining
walls. Many times soil nailing can be the least disruptive way to construct retaining
systems.
Soil nailing not only works in tension but also with bending and shearing forces.
Generally, the soil nails increase the bonding of the soil through their ability to carry
tensile loads. A constructed face is usually required and is typically made of shot Crete,
which is reinforced with wire mesh and steel plates. Permanent walls are usually
constructed with cast in place facing.
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Soil Nailing Construction
CHAPTER NO.2
SOIL NAILS
2.1 NAILS
Soil nails are installed in a pattern designed to ensure both internal and external
stability of the wall. A relatively large number of nails are placed so they can resist the
tensile, compressive, and shear stresses within the wall and transfer them into the ground.
Engineers use a method of equilibrium analysis to make certain that the number and
placement of nails guard against sliding and guarantee stability.
The nails used in construction are generally steel bars that resist tensile and shear
stresses and bending moment. Therefore, ductile steel is preferred over brittle. Most
projects are designed to use nails with a uniform length and cross-sectional area. Nail
length is usually about 60-80% of the height of the wall, depending on soil conditions
(e.g., rocklike material may get shorter nails). Prior to construction, nails are tested to
determine nail-soil adhesion and their resistance to pullout failure.
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2.1.1 Typical Section Of Soil Nail
2.2 TYPES OF NAILS
● Driven nail
● Grouted nail
● Corrosion-protected nails
● Launched nails
● Jet grouted nail
2.2.1 DRIVEN NAILS: Driven nails are small-diameter (15 to 46mm) rods or bars, or metallic sections,
with a relatively limited length (to about 20m) made of mild steel with a yield strength
of 350MPa (50ksi). They are closely spaced (2 to 4 bars per square meter) and create a
rather homogeneous composite reinforced soil mass. The nails are driven into the ground
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Soil Nailing 2014-15 at the designed inclination using a vibropercussion pneumatic or hydraulic hammer with
no preliminary drilling. Special nails with an axial channel can be used to allow for grout
sealing of the nail to the surrounding soil after its complete penetration. This installation
technique is rapid and economical (4 to 6 per hour). However, it is limited by the length
of the bars (maximum length about 20m) and by the heterogeneity of the ground (e.g.,
presence of boulders).
2.2.2 GROUTED NAILS:
Grouted nails are generally steel bars (15 to 46mm in diameter) with a yield
strength of 60 ksi. They are placed in boreholes (10 to 15cm in diameter) with a vertical
and horizontal spacing varying typically from 1 to 3m depending on the type of the in-
situ soil. The nails are usually cement-grouted by gravity or under low pressure. Ribbed
bars can be used to improve the nail-grout adherence, and special perforated tubes have
been developed to allow injection of the grout through the inclusion.
2.2.3 CORROSION-PROTECTED NAILS:
Corrosion-protected nails generally use double protection schemes similar to
those commonly use in ground anchor practice. For permanent applications of soil
nailing, based on current experience, it is recommended that a minimum grout cover of
1.5 inches be achieved along the total length of the nail. Secondary protection should be
provided by electro statically applied resin-bonded epoxy on the bars with a minimum
thickness of about 14 mm. In aggressive environments, full encapsulation is
recommended. It may be achieved, as for anchors, by encapsulating the nail in corrugated
plastic or steel tube grouted into the ground.
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2.2.4 LAUNCHED NAILS:
The nail launching technology consists of firing directly into the ground, using a
compressed air launcher, nails of 25mm and 38mm in diameter, made from bright bar
with nail lengths of 6 meters or more. The nails are installed at speeds of 200 mph with
an energy transfer of up to 100kJ. This installation technique enables an optimization of
nail installation with a minimum of site disruption. During penetration the ground around
the nail is displaced and compressed. The annulus of compression developed reduces the
surface friction and minimizes damage to protective coatings such as galvanized and
epoxy. The technology is presently used primarily for slope stabilization although
successful applications have also been recorded for retrofitting of retaining systems.
However, a rigorous evaluation of the pull-out resistance of launched nails is required
prior to their use in retaining structures.
2.2.5 JET-GROUTED NAILS:
Jet-grouted nails are composite inclusion made of a grouted soil with a central steel
rod, which can be as thick as 30 to 40 cm. a technique that combines the vibropercusion
driving and high pressure (greater than 20 MPa) jet grouting has been developed by
Louis (1986). The nails are installed using a high frequency (up to 70Hz) vibropercussion
hammer, and cement grouting is performed during installation. The grout is injected
through a small-diameter (few millimeters) longitudinal channel in the reinforcing rod
under a pressure that is sufficiently high to cause hydraulic fracturing of the surrounding
ground. However, nailing with a significant lower grouting pressure (About 4MPa) has
been used successfully, particularly in granular soils. The inner nail is protected against
corrosion using a steel tube.
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Soil Nailing 2014-15 2.3 SOIL NAIL INTERACTION:
In soil nailing, similarly to ground anchors, the load transfer mechanism and the
ultimate pull-out resistance of the nails depend primarily upon soil type and strength
characteristics, installation technique, drilling method, size and shape of the drilled hole,
as well as grouting method and pressure used.
To date, estimates of the pull-out resistance of nails are mainly based upon
empirical formulae (or ultimate interface shear stress values) derived from field
experience. These formulae are useful for feasibility evaluation and preliminary design.
Table (Elias and Juran, 1991) provides a summary of estimated ultimate interface shear
stress values for soil nails as a function of soil type and installation technique.
2.3.1 Estimated ultimate interface lateral shear stress values for soil nails:
Construction Method Soil Type Ultimate Lateral Shear
Stress, kip/ft
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Rotary drilled Silty sand 2 to 4
Silt 1.2 to 1.6
Piedmont residual 1.5 to 2.5
Driven casing Sand 6
Dense Sand / Gravel 8
Dense moraine 8 to 12
Sandy colluviums 2 to 4
Clayey colluviums 1 to 2
Jet grouted Fine Sand (Medium Dense) 8
Sand/gravel 20
Augured Soft Clay 0.4 to 0.6
Stiff and Hard Clay 0.8 to 1.2
Clayey Silt 1 to 2
Calcareous sandy clay 4 to 6
Silty Sand Fill 0.4 to 0.6
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CHAPTER-3
CONSTRUCTION
3.1 SOIL NAIL COMPONENTS:
1. The in-situ ground
2. Tension-resisting nails
3. Facing or the structural retaining element.
The nails used in soil-nailing retaining structures, are generally steel bars or other
metallic elements that can resist tensile stresses, shear stresses, and bending moments.
They are generally either placed in drilled boreholes and grouted along their total length
or driven into the ground. The nails are not pre-stressed but are closely spaced (e.g., one
driven nail per 2.5 ft², one grouted nail per 10-50 ft²) to provide an anisotropic apparent
cohesion to the native ground. A variety of proprietary nails, corrosion-protection
systems, and installation techniques such as coupling nail driving with jet grouting,
driving encapsulated nails, or driving prefabricated nails that consist of pre-stressed bars
in compression tubes have been used in permanent structures.
The facing of the soil-nailed structure is not a major structural load-carrying element
but rather ensures local stability of the soil between reinforcement layers and protects
the ground from surface erosions and weathering effects. It generally consists of a thin
layer of reinforced shotcrete (4- to 6-in thick), constructed incrementally from the top
down. Prefabricated or cast-in-place concrete panels have increasingly been used in the
construction of permanent structures to satisfy specific aesthetic and durability design
criteria and to accommodate adequate facing drainage.
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Construction of Soil Nailed wall
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3.2 Operations in Soil Nailing:
3.2.1 Placement of Nails: The equilibrium design is site-specific and determines nail placement. The
commonsense rule of thumb is that greater performance results from more nails closely
spaced, rather than fewer nails widely spaced. Typically, nails of equal length and cross-
sectional area are uniformly spaced. In general, for drilled and grouted nails, spacing
is one nail per 3—6.5 ft., both vertically and horizontally. Driven nails require higher
densities of as much as one and a half to two nails per square meter. Nail rows are often
staggered to increase face stability. The angle of inclination is generally between 10 and
20°
Nail length depends on several factors, including soil strength, soil nail adhesion,
and the overall loading of the system. In general, minimum nail length is considered to be
about 0.6 times the wall height for vertical walls with no back slope. Shorter nails have
been used in walls with more rocklike soils.
The vast experience (in Europe) indicates that it might be preferable in some
cases to install longer and higher-capacity nails in the upper two-thirds of the wall, as
research shows that this reduces wall displacement. Though arguments have been made
to the contrary, longer and heavier nails in the upper part of the wall seem to be more
effective in preventing failure than reinforcements in the lower wall. Overall, though,
uniform length, strength, and placement yield good results.
3.2.2 Grouting:Neat cement grout with a water-to-cement ratio of about 0.4:0.5 is usually used.
In many cases for open-hole drilling, the low-pressure tremie method works well. In
Germany, the nail may be installed with a regrout pipe attached, and the grout is added
under pressure, fracturing the initial grout and creating a better bond between the grout
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Soil Nailing 2014-15 and the soil. In general, grout may be added either before or after installation of the nail.
3.2.3 Facing:Once the nails are installed and grouted, a shot Crete facing between 3 and 6 in.
thick is applied, with a wire mesh at mid-thickness. This is generally used for temporary
wall facings. Permanent walls may receive a shot Crete cover of up to 10 in. thick,
usually with a second layer of wire mesh. In both of these cases, the facing is not
considered to be a structurally significant supporting part of the wall.
The experience in France indicates that nail loads at the facing generally do not
exceed 30-40% of the maximum loads in the nail, so they recommend a facing designed
for a uniform wall pressure equal to 60% of the maximum nail load on a nail spacing of 3
ft. For walls with greater nail spacing (e.g., 10 ft.), the facing should be designed for
100% of the maximum nail load. Permanent structures can be made more pleasing to the
eye with the addition of cast-in-place concrete facings with a minimum of 8-in. thickness.
Precast decorative panels may also be attached directly to the shot Crete facing.
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3.3 Sequence of Construction:This style of slope stabilization requires drilling through the active zone into the
passive area of the soil bank.
1. A five foot cut is made to begin the first lift of nails.
2. Holes are drill to depth on about five foot centers.
3. Threaded nails with centralizes are placed in holes.
4. Nails are then grouted in place from bottom up
5. Wire mesh and bars are installed over the face.
6. First coating of shot Crete is applied to face of cut.
7. Plates, washers, and nuts installed on nails.
8. Second coat of shotcrete applied over plates.
9. Repeat steps one through eight for each lift.SINHGAD ACADEMY OF ENGINEERING, PUNE-48 Page 18
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3.3.1 Excavation of small cut 3.3.2 Drilling
3.3.3 Grouting 3.3.4 Facing
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3.3.5 Subsequent Levels 3.3.6 Final Facing
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CHAPTER-4
DESIGN CONCEPTS4.1 Engineering behavior and Design concepts:
The basic design concept of soil-nailed retaining structures relies upon the
transfer of resisting tensile forces generated in the inclusions into the ground through
friction at the interfaces. The frictional interaction between the ground and the quasi "non
extensible" steel inclusions restrain the ground movement during and after excavation.
The resisting tensile forces mobilized in the inclusions induce an apparent increase of
normal stresses along potential sliding surfaces increasing the overall shear resistance of
the native ground. The main engineering concern in the design of these retaining systems
is to ensure that ground-inclusion interaction is effectively mobilized to restrain ground
displacements and can secure the structure stability with appropriate factor of safety.
4.2 Design Methods For Soil Nailed Retaining Structures:The available design methods for soil nailed retaining structures can be broadly
classified into two main categories.
4.2.1 Limit equilibrium design methods or modified slope stability analyses, which
are used to evaluate the global safety factor of the nailed structures with respect to a
rotational or translational failure along potential sliding surfaces, taking into account the
shearing, tension, or pull-out resistance of the inclusions crossing the potential failure
surface.
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Soil Nailing 2014-15 4.2.2 Working stress design method which is used to estimate the tension and shear
forces generated in the nails during construction under the design loading conditions and
evaluates the local stability at each level of nails.
The design procedure for a soil-nailed retaining structure should include the following
steps:
1. For the specified structure geometry (depth and cut slope inclination), ground
profile, and boundary (surcharge) loadings, estimate working nail forces and
location of the potential sliding surface
2. Select the reinforcement type (type, cross-sectional area, length, inclination,
and spacing) and verify local stability at each reinforcement level, that is, verify
that nail resistance (strength and pull-out capacity) is sufficient to withstand the
estimated working forces with an acceptable factor of safety.
3. Verify that the global stability of the nailed-soil structure and the surrounding
ground is maintained during and after excavation with an acceptable factor of
safety.
4. Estimate the system of forces acting on the facing (i.e., lateral earth pressure and
nail forces at the connection) and design the facing for specified architectural and
durability criteria.
5. For permanent structures, select corrosion protection relevant to site conditions.
6. Select the drainage system for groundwater levels.
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4.3 Seismic Design Of Soil Nailed Retaining Structures:
Of particular importance for earthquake zones is the seismic performance of soil
nailed excavations which has been observed during the 1989 Loma Prieta Earthquake in
the San Francisco Bay, where several soil nailed structures were subjected to significant
levels of shaking (Barar, 1990; Felio et al., 1990). Soil nailed structures are systems that
are coherent and flexible. Therefore, they present inherent advantages of withstanding
larger deformations with high resistance to dynamic loadings. Due to these advantages,
these systems appear to offer a valuable and cost effective technical solution for
geotechnical construction in seismic zones. The high performance of soil nailed systems
to earthquake loading in seismic zones was demonstrated by post earthquake
observations (Barar,1990; Felio et al., 1990). Centrifugal model tests have been
conducted by Vucetic et al., (1993 and 1996) to evaluate the failure mechanisms of soil
nailed structures under seismic loading. However to date, only limited studies have been
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Soil Nailing 2014-15 conducted to evaluate the dynamic response of soil nailed structures and a
comprehensive investigation is needed in order to develop and experimentally evaluate
reliable seismic design methods.
During the past decade, the observed performance of soil nailed structures under
earthquake loading conditions raised a significant need for the development and
experimental evaluation of reliable seismic design methods. The design methods most
currently used for seismic stability analysis of soil nailed systems are derived from the
pseudo-static Mononobe-Okabe analysis. Two fundamentally different pseudo-static
design approaches have been developed: (i) the global limit equilibrium analysis and (ii)
the working stress analysis.
4.3 Research and Development:A significant research and full scale experiments have been conducted during the
past decade to develop and evaluate reliable analysis methods and establish relevant
design codes. It is worth noting that in France, a National Research Project
CLOUTERRE was conducted from 1986 to 1990 with a total budget of 22M French
Francs, which resulted in the development of the CLOUTERRE 1991 Recommendations
(translated into English by the Federal Highway Administration, 1991). In the United
States, the engineering use of this technology for temporary and permanent structures is
currently growing with increasing local experience (Abramson and Hansmire, 1988;
AASHTO, 1990; Bruce and Jewell, 1987; Fannin and Bowden, 1991; Nicholson, 1986;
Thompson and Miller, 1990), and both federal and state DOTs increasingly recognize the
specific advantages of this technology (Chassie, 1994). In particular, the research
conducted by the FHWA (Elias and Juran, 1991; Byrne et al, 1996) has resulted in
the development of a manual of practice for design, construction, quality control, and
monitoring of soil-nailed structures.
The increasing use of soil nails in permanent structures is a key parameter in
current technological developments. Durability of the inclusions, long-term performance
in fine-grained soil, and environmental/architectural requirements for soil-nailed facing
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Soil Nailing 2014-15 have become major design considerations. It should be emphasized that further
experimental research and particularly centrifugal and shaking table model testing is
necessary in order to establish a statistically significant data base for the seismic
performance assessment as well as for the development and experimental evaluation of
reliable seismic design methods for the engineering use of soil nailing in earthquake
zones.
CHAPTER-5
Pluses, Minuses & ApplicationsSoil nail walls compare favorably with other soil-retention construction systems.
Tieback walls, for example, require structural facing elements that are pre-tensioned and
anchored to the ground with steel that is strong and stiff enough to hold the soil structure
behind it. The anchors must be tensioned with enough loads to support the facing without
creep or other failure. Unlike tiebacks, soil nail walls are not tensioned; they are passive
reinforcements that, once placed within the soil of the wall, create a coherent gravity
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Soil Nailing 2014-15 mass. Thus, soil nails create a condition of internal stability within the wall; stability does
not depend on the strength of the outer facing but is generated within the structure itself.
Further, soil nail construction eliminates the need for placing H-piles, timber lagging, or
sheet piling, as well as the need for costly facing systems. The nail length is shorter than
that used in tiebacks, improving traffic flow around highway construction projects.
In mechanically stabilized earth (MSE) walls, which are somewhat akin to soil
nail walls, the greatest amount of stress accumulates at the bottom of the wall through
compaction. Thus, the lower parts of an MSE wall are most likely to deform or fail. In a
soil nail wall, the greatest stress is initially contained within the upper layers of the wall,
then passes downward as construction proceeds. Unlike MSE walls, however, the
placement of more and/or longer nails in the upper portion of the soil nail wall seems to
limit the transfer of tension to the lower wall. Studies have shown that, over time, the
stress within the soil nail wall reaches equilibrium at all levels.
5.2 Benefits of Soil Nail:● Minimum vibration or displacement of soil during installation.
● Less underground easement necessary than with conventional tie-back anchors.
● The system can be installed underneath an existing structure, thus saving the
lateral space usually required by other sheeting and shoring methods.
● Loss of ground can be prevented.
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● Height of wall is not restricted.
● Can be constructed with architecturally pleasing precast panels.
● Can be used as both temporary and permanent support.
● Soil nail walls can be built to follow curved or zigzagged outlines.
● The equipment used is highly portable and can fit easily into small spaces.
● Construction causes less noise and traffic obstruction on highways.
● The process creates less impact on adjacent or nearby properties than do other
construction methods, so settlement of adjacent building can be prevented.
● It generally requires less space and manpower.
5.3 Drawbacks of Soil Nailing:● The method cannot be used at sites where groundwater is a problem.
● It is inappropriate for sites with soils having very low shear strength, in sand and
gravels that lack cohesion, and on sites with other unsuitable soils.
● Soil must be able to stand unsupported while it is being nailed and before shot
Crete application.
● Good drainage is essential, especially for permanent structures and in places
prone to freeze-thaw cycles.
● Soil nailing is not practical to Soft, plastic clays.
● Soil nailing is not practical to Loose (N<10), low density and/or saturated soils.
5.4 Applications of Soil Nailing:
● To stabilize slopes and landslides.
● To support and strengthen ground around tunnel excavations.
● To provide an earth retention system for deep excavations.
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● To create a permanent retaining wall.
● To offer temporary shoring during the repair of an existing wall.
● To control ground disturbance.
● To help in the preservation of natural areas.
● To stabilize vertical cuts in front of existing bridge abutments during highway
widening operations.
● For stabilization of railroad and highway cut slopes.
● For excavation retaining structures in urban areas for high-rise building and
underground facilities.
CHAPTER-6SINHGAD ACADEMY OF ENGINEERING, PUNE-48 Page 28
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CASE STUDY“NAILED SOIL WALL FOR LANDSLIDE PROTECTION AT NAINITAL”
LOCATION OF SITE:
The site is located on Nainital-Haldwani road, about 4 kms from Nainital.
Designed By:
Dr. Satyendra Mittal
Dr. Meenal Gosavi (Gulati)
(Indian Institute of Technology, Roorkee.)
Statement of Problem:
● Due to landslide which occurred two years back, sewage pipe line is broken
which has in free flow of water from pipe.
● Exposed end of pipe (with free flow of sewage water) has not only caused fouling
smell there but also caused serious environment threat.
● Broken sewage pipe line had to be restored as early as possible as the continuous
open flow was causing undermining of existing slopes and since the first day of
breakage of pipe, these slopes have further deteriorated.
● Indian Institute of Technology, Roorkee suggested the solution to stablize the
slopes on both sides of exposed sewage pipeline causing nallah.
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View Of Sever Outfall
Input Parameters:
Sr. No. Parameter Detail
1 Type Of Soil Ø Soil
2 Angle of internal friction (Ø) of soil material 42.5˚
3 Vertical Height of slope 16 m
4 Angle of slope with vertical 10˚
5 Cohesion (C) 0
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Re-alignment of Existing Slopes
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Proposed design:
Sr. No. Parameter Details
1 Method Of Soil Nailing Grouted Nail
2 Horizontal & vertical spacing of nail 1.0 m
3 Length of nail 6.4 m
4 Material of Nail Tor-Steel
5 Diameter of Nail 25 mm
6 Bore Hole Diameter 100 mm
7 Mix Design 1:1.5:3
8 F.O.S. 2.5
9 Inclination of nail with horizontal 10˚
10 Facing Chicken mesh
Location Of Site:Saptashrungi Gadh, Vani (Nashik)
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Project By:MACCAFERRI INDIA LTD.
Cost Of Project:21Crores
Input Parameters:
Sr. No. Parameter Details
1 Type Of Strata Available 69 Million Years Old Deccan Basalt
2 Weather Condition Highly Weathered
Failure Type:
Topple Falling
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Soil Nailing 2014-15 Proposed Design:
Sr. No. Parameter Details
1 Type Of Nail Grouted (Shrinkcom Grout)
2 Length of Nails 3 m
3 Facing Steel Mesh
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CONCLUSIONThe fundamental concept of soil nailing consists of reinforcing the ground by
passive inclusions, closely spaced, to create in-situ a coherent gravity structure and
thereby to increase the overall shear strength of the in-situ soil and restrain its
displacements. The basic design consists of transferring the resisting tensile forces
generated in the inclusions into the ground through the friction mobilized at the interfaces.
Also if the site is influenced by ground water, the technique may not be proved to
be effective.
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REFERENCESBooks:• Indian Geotechnical Journal, 31(4), 2001.
• Indian Geotechnical Journal, 32(2), 2002.
• Indian Geotechnical Journal, 12(2), 1982.
Websites:• http://www.forester.net
• http://www.tc17.poly.edu
• http://www.rembco.com
• http://www.schnabel.com/schnabel
• http://www.canltd.uk/geotech
• http://www.ates-india.com/experts/manojverman.htm
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