soil nailing

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

Soil Nailing 2014-15 SAOE, Pune.



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



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.



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.



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.



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


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.



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.


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



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



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.



Construction of Soil Nailed wall



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


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.



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


3.3.1 Excavation of small cut 3.3.2 Drilling

3.3.3 Grouting 3.3.4 Facing



3.3.5 Subsequent Levels 3.3.6 Final Facing



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.


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.



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


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


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


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.



● 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.



● 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


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.



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



Re-alignment of Existing Slopes



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)



Project By:MACCAFERRI INDIA LTD.

Cost Of Project:21Crores

Input Parameters:


1 Type Of Strata Available 69 Million Years Old Deccan Basalt

2 Weather Condition Highly Weathered

Failure Type:

Topple Falling


Soil Nailing 2014-15 Proposed Design:


1 Type Of Nail Grouted (Shrinkcom Grout)

2 Length of Nails 3 m

3 Facing Steel Mesh



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.



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


soil nailing

Engineering

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seminar report

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typical soil nail details

guidance of

t120430086 of te civil

abhijit ashok

situ reinforcement technique