Soil nailing

EXPERIMENTAL STUDY FOR COMPARISON OF ULTIMATE LOAD IN COHESIONLESS SOIL BY SOIL NAILING – HORIZONTAL V/S

INCLINED NAILED

Dharmsinh Desai University, Faculty Of Technology

Nadiad

Prof. Samirsinh P ParmarAsst. Professor,

Department of Civil EngineeringMail: [email protected]

OUT LINE OF PRESENTATION

2

Introduction

Literature Review

Analytical Study

Experimental Study

Conclusion

Future Scope

References

INTRODUCTION

Soil nailing is the method of reinforcing the soil with steel bars or other material.

It has been alternative technique to other conventional supporting system as it offers flexibility, rapid construction & competitive cost.

The purpose is to increase the Tensile & Shear Strength of the soil & Restrain its displacements.

Soil nailing is a construction technique used to reinforce soil to make it more stable.

In this technique, soil is reinforced with slender elements such as reinforcing bars which are called as nails. These reinforcing bars are installed into pre-drilled holes and then grouted.

3

Soil nailing technique is used for slopes or excavations alongside highways, railway lines etc.

4Figure:- Soil Nailing In Railway Construction

CONSTRUCTION SEQUENCE

Excavation of Slope

Drilling Nail Holes

Nail Installation and Grouting

Construction of Temporary Shotcrete Facing

Construction of Subsequent Levels

Construction of a Final, Permanent Facing

5

APPLICATIONS Soil Nail Walls for Temporary and Permanent Cut Slopes Retaining Structure under Existing Bridge Abutments Repair and Reconstruction of Existing Retaining Structures

6

ADVANTAGES OF SOIL NAILING

• Economic Advantage10% to 30% saving in cost when compared to an Anchored Diaphragm Wall.

• Simple & Light Construction Equipment- Drilling Ring for nail installation- Guns for shotcrete application

• Adaptability to Site ConditionsIn heterogeneous ground where boulder or hard rocks may be encountered. 7

• SpaceSoil nailing provides an obstruction free working space which can result in

considerable reduction in construction time for basement works and tunnel construction.

• Structure StabilitySoil nailing use large number of nails, so failure of any one nail may not be

determine to the structure stability.

8

LIMITATION OF THE SYSTEM

It requires cuts which can stand unsupported for depths of about 1 to 2 m at least for a few hours prior to shotcreting & nailing. Otherwise a pretreatment such as grouting may be necessary to stabilize the face.

Soil nail walls are not well-suited where large amounts of groundwater seep into the excavation because of the requirement to maintain a temporary unsupported excavation face.

Construction of soil nail walls requires specialized and experienced contractors.

9

COMPONENTS OF THE SYSTEM

Figure:- Component of Soil Nail Wall10

SCOPE OF WORK

11

This dissertation is divided into two parts.

1) Experimental Work on Soil Nail WallThe main aim of this study is to evaluate, how the soil nailed structure behaves at different Inclination of Nailed Angle i.e. 10°, 15° and different L (length of nail )/H (height of the wall) ratio i.e. 0.6, 0.7, 0.8 in comparison to Horizontal Nailing, i.e. 0° inclination. The Vertical Spacing (Sv) and Horizontal Spacing (Sh) is 10 cm between two nails.

This experimental work has been carried out in a laboratory by using 12 mm dia. Steel Bars (12 nos.) as nail on Cohesionless Soil (Poorly Graded Sand) in a Tank (size: 100 × 50 × 80 cm) at a Relative Density of 50%. Wooden ply board (size: 1.9 × 50 × 80 cm) was used as a Rigid Facing. Maximum ultimate load has been found out by applying the load up to the nailed wall failure.

2) Analysis of Soil Nailed WallAnalysis of soil nail wall using method proposed by Ramlingaraju (1996) and Gupta (2003) are based on Moment Equilibrium Approach assuming the rupture surface as log-spiral meeting the ground at 90°.

The calculation for the Factor of Safety has been shown using Excel tool.

12

LITERATURE REVIEW

ANALYTICAL STUDY

• The design of a soil nail wall should ensure that the system is safe against all of the potential failure conditions are

External Failure ModeInternal Failure ModeFacing Failure Mode

13

• External Failure Modes

Global Failure Mode

Davis Deign Method

German Design Method

Kinematical Limit Analysis

French Multicriteria Analysis

Ramlingaraju and Gupta Design Method

Sliding Failure Mode

Bearing Failure Mode 14

THEORETICAL BACKGROUND

The methods proposed by Ramligaraju (1996) and Gupta (2003) are based on Moment Equilibrium Approach assuming the rupture surface as log-spiral meeting the ground at 90°.

15

16

MWV = Moment of W (1 ± αv) about ‘O’

MWH = Moment of W*αh about ‘O’

Mqv = Moment of Q (1 ± αv) about ‘O’

Mqh = Moment of Q*αh about ‘O’

Mc = Moment of Cohesion about ‘O’

𝐅 .𝐎.𝐒=∑ 𝐓 𝐢∗ 𝐥𝐢+∑ 𝐓𝐜𝐢∗ 𝐥𝐜𝐢+𝐌𝐜

𝐌𝐰𝐯+𝐌𝐰𝐡+𝐌𝐪𝐯+𝐌𝐪𝐡

MWV = Moment of W (1 ± αv) about ‘O’=

MWH = Moment of W*αh about ‘O’=

17

Mqv = Moment of Q (1 ± αv) about ‘O’

=

Mqh = Moment of Q*αh about ‘o’

=

Mc = Moment of cohesion about ‘O’

18

19

𝐅 .𝐎.𝐒=∑ 𝐓 𝐢∗ 𝐥𝐢+∑ 𝐓𝐜𝐢∗ 𝐥𝐜𝐢+𝐌𝐜


= Mobilized shear in ith nail.It acts normal to the nail axis

𝐓𝐜𝐢=𝐂∗𝐌𝐩𝐥𝐬𝐢∗𝐒𝐡 [𝟏−( 𝐓 𝐢

𝐓𝐩 )]

Figure:- Forces acting on the Wedge ‘abd’

lciα

20Figure:- Forces acting on the Wedge ‘abd’

= Axial force in the ith nail at the point of maximum bearing moment

𝑻 𝒊= (𝐜+𝝈𝒏𝒊 𝒕𝒂𝒏𝜹 )𝒑𝒊𝑳𝒆𝒊 /𝑺𝒉

𝐅 .𝐎.𝐒=∑𝐓 𝐢∗ 𝐥𝐢+∑ 𝐓𝐜𝐢∗ 𝐥𝐜𝐢+𝐌𝐜


li

α

= Length of the ith nail behind the failure surface


= Fully plastic axial force

A = c/s area of the nail =

d = Diameter of nail

D = Grout hole diameter

= γ * Depth of nail from top

= Fully plastic moment capacity of nail (depends on nail yield stress and shape of nail).

= Yield stress of nail. = Shear width C = 4 (Range 2 to 5)

21

𝐓𝐜𝐢=𝐂∗𝐌𝐩𝒍𝒔𝒊∗𝐒𝐡 [𝟏−( 𝐓 𝐢

𝐓𝐩 )]


c = Unit cohesion of the soil.

δ = Mobilized soil-nail interface friction angle =

= Perimeter of the ith nail

= Length of the ith nail behind the failure surface

f1 = limit bond stress of the soil nail interface. (ith obtained from pull-out test.)

ϴ = Nail inclination with horizontal

= Normal stress at the mid depth of ith nail in the length.

,

= Coefficient of active earth pressure

Horizontal spacing between two nails 22

𝐓𝐜𝐢=𝐂∗𝐌𝐩𝐥𝐬𝐢∗𝐒𝐡 [𝟏−( 𝐓 𝐢

𝐓𝐩 )]

Illustrative Example

RAMLINGARAJU AND GUPTA METHOD• Height of wall, H = 8 m• Φ = 30⁰• c = 2 kN/m2

• ϒ = 18 kN/m3

• Surcharge, q = 8 kN/m2

• Nail inclination, θ = 10⁰• fy =250000 kN/m2

• Length of Nail = 6.4 m• Log-spiral failure angle, α = 35⁰• Horizontal and Vertical Spacing, Sv & Sh = 0.7 • Number of nail required, n = 11

23

Forces Acting on the Wedge1) Weight W of the wedge ‘abd’ along with vertical seismic force, i.e. W (1 ±)

W = Wt. of ‘Obd’ – Wt. of ‘Oed’ – Wt. ‘aed’

Moment M1 of Wt. W1 of ‘Obd’ about “O”.

= 4039.21 kN m/m

Moment M2 of Wt. W2 of ‘Oed’ about “O”.

24

Moment M3 of Wt. W3 of ‘aed’ about “O”.

2) Moment of W * about “O”.Moment M4 of W1 * about “O”.

Moment M5 of W2 * about “O”.

Moment M6 of W3 * about “O”.

25

3) Moment at Q about “O”.

Moment of Q * (1 ±) about “O”.

Moment of Q * about “O”.

4) Moment of Cohesion force c about “O”.

26

From trial and error, we get

5) Moment due to pull-out resistance of the length of nails behind the slip surface

27

6) Moment of the mobilized shear acting in the nail normal to their axis

28

29

30

Excel Sheet

8 m α 35 degree8 kN/m2 θ 10 degree2 kN/m2 Sv 0.70 m30 degree Sh 0.70 m18 kN/m3 αh 0.10

αv 0.05fy 250 N/mm2

25 mm n 1125 mm i 1

6.40 m C 4

RAMLINGRAJU & GUPTA METHOD, Vertical Wall

Height of nailed wall, H

Ka

Length of Nail, L

0.33Nail Diameter, d

Groute Diameter, D

INPUTS

Unit weight of soil, γδ 20

Surchrge, qcɸ

Ramlingaraju and Gupta Method

M1 =4278.27 kN-m

δ =12.29 deg

M2 =1095.21 kN-m

M3 =1298.74 kN-m

Mwv =1978.54 kN-m

{γ*H3*x3/[3(1+9*tan2ϕ)]} * [e3*α*tanϕ{3*tanϕ*cos(ϕ+α)+sin(ϕ+α)} - 4*sinϕ]

cot-1[(1/sinϕ)*(2*sin(ϕ+α)/sinα) - cosϕ]

1/12*γ*H3*x3*{sin3α/sin3(ϕ+α)}*{sin(ϕ+δ)*sin2ϕ*cos(ϕ+δ)/sin2δ}

1/2*γ*H3*cot(ϕ+α)*[x*cosϕ - y - (cot(ϕ+α)/3)]

(1±αv)*(M1 - M2 - M3)

M4 =519.87 kN-m

M5 =99.62 kN-m

M6 =208.07 kN-m

Mwh =212.18 kN-m

1/2*γ*H3*αh*cot(ϕ+α)*[x*sinϕ + 1/3)]

M4 - M5 - M6

{γ*H3*x3*αh/[3(1+9*tan2ϕ)]}*[e3*α*tanϕ{3*tanϕ*sin(ϕ+α)-cos(ϕ+α)}-3*tanϕ*sinϕ+cosϕ]

1/12*γ*H3*x3*αh*{sin3α/sin3(ϕ+α)}*{sin2(ϕ+δ)*sin2ϕ/sin2δ}

31

32

Mqv = Mqh =169.96 kN-m 11.05 kN-m

Mc =183.19 kN-m(c*H2*x2/2*tanϕ)*(e2*α*tanϕ - 1)

q*H2*y*[x*cosϕ - y/2]*[1±αv] q*H2*αh*x*y*sinϕ

li = lci =4.30 m 9.16 m

Ti = Tp = fy*A2.77 kN 122.5 kN

Tci =1.80 kN

Mpi = Msc =11.91 kN-m 16.49 kN-m

{(C*Mp)/(lsi*Sh)}*[1-(Ti/Tp)]

Ti * li Tci * lci

On*sin(ϕ+αi-θ)

(c + σni*tanδ)*Pi*lei / Sh

On*cosϕ

33

n = 11 αi li lci Ti Tci Mpi Msc1 4.00 4.30 9.16 2.77 1.80 11.91 16.492 7.20 4.99 9.46 4.57 2.45 22.8 23.183 10.20 5.66 9.75 6.43 2.93 36.39 28.574 13.20 6.36 10.05 8.53 3.36 54.25 33.775 16.10 7.04 10.35 10.82 3.68 76.17 38.096 19.00 7.74 10.65 13.45 3.98 104.1 42.397 21.80 8.44 10.96 16.36 4.23 138.08 46.368 24.50 9.12 11.27 19.59 4.46 178.66 50.269 27.20 9.80 11.57 23.29 4.63 228.24 53.57

10 29.90 10.50 11.89 27.49 4.80 288.65 57.0711 32.50 11.19 12.21 32.12 4.89 359.42 59.71

1498.67 449.46

i =

0.9۴ = S۽��σ ܔ�܂ �ܖ�స ା�σ ܋ܔ܋܂ ା� ܖ܋ۻ�

�స� ା� � ା� ା� ൌ��

34

6 m α8 kN/m2 i2 kN/m2 αh

38 degree αv

18 kN/m3 λ (+) ve sign (-) ve sign250 kN/m2 5.44 6.01

Kad 0.286 0.265Max. Kad

250000 kN/m2

Bearing Capacity of soil

Static Case Seismic CaseHeight of nailed wall, H 0

Surchrge, q 0c 0.10ɸ 0.05

Unit weight of soil, γ

δKa 0.286fy

25.340.217

ANALYSIS OF SOIL NAIL WALL

Swami Saran

Paϒ = Paϒi =70.31 kN/m 22.36 kN/m

Paq = Paqi =10.42 kN/m 3.32 kN/m

Pac = PTs =11.18 kN/m 25.68 kN/m

PTst =69.55 kN/m

Maϒ = Maϒi =140.62 kN-m/m 67.08 kN-m/m

Maq = Maqi =31.26 kN-m/m 13.28 kN-m/m

Mac = MTs =33.54 kN-m/m 80.36 kN-m/m

MTst = 138.34 kN-m/m

(Kad - Ka) * q * H

Paϒ + Paq - Pac

Paϒi + Paqi2*c*Ka1/2*H

Total Earth Pressure & Moments Dynamic Increment & Moment

Paϒ * H/3

Maϒ + Maq - Mac

Paϒi * H/2

Maϒi + Maqi

Paq * H/2 (2/3) * Paqi * H

0.5 * Ka * ϒ * H2 0.5 * (Kad - Ka) * ϒ * H2

Ka * q * H

c*Ka1/2*H2

25 mm μ 0.54.8 m L/H 0.8

Ww = ϒ * H * L Wswh = Ww * αh Wswv = ± Ww * αv

kN/m 518.40 51.84 25.92Mw = Ww * L/2 Mswh = Ww * H/2 *αh Mswv = ± Ww * L/2 * αv

kN-m/m 1244.16 155.52 62.21Q = q* L Psqh = q * L * αh Psqv = ± q * L * αv

kN/m 38.40 3.84 1.92Mq = q * L2/2 Msqh = Q * H * αh Msqv = Q * L/2 * αv

kN-m/m 92.16 23.04 4.61

Diameter of nails, d

Static Case

Force & Moments related Nail Soil Excavation

Seismic Case

Assume Length of nails, L

35

36

External Stability Sliding

Static Case Seismic Case

Fs =μ (Ww + Q)/PTst Fs =μ (Ww + Q)*(1 ± αv)/(PTst + Paϒi + Paqi + (Ww + Q)*αh

4.00 > 2, Safe 1.94> 1.5, Safe Overturning

Static Case Seismic Case

Fo =(Mw + Mq) / MTst Fo =(Mw + Mq + Mswv + Msqv)/(MTst + Maϒi + Maqi + Mswh +Msqh)

9.66 > 2, Safe 3.54> 1.5, Safe Tilting / Bearing Failure

Static Case Seismic Case SBC (kN/m2)=250

σmax = [(Ww + Q)/L] + (MTst * 6/L2) σmax =[(Ww+Q)*(1±αv)/L] + ((MTst + MTs + Mswh + Msqh) * 6/L2)

152.03< SBC, Safe 225.26< SBC, Safe

σmin = [(Ww + Q)/L] - (MTst * 6/L2) σmin =[(Ww+Q)*(1±αv)/L] - (MTst + MTs + Mswh + Msqh) * 6/L2)

79.98> 0, Safe 18.35> 0, Safe

37

hi 6 mσvi = σvi =

152.03 kN/m2 248.21 kN/m2

M1 = M1 =

138.33 kN-m/m 226.52 kN-m/m

Assume Ma iϒ = ϒ(Kad-Ka) hi3

(2H-hi) / 4HMaqi =

q(Kad-Ka) hi2

(3H-hi) / 3HFnail = 67.07 kN-m/m 13.25Fmax = M3 =

31.13 * Sv2 485.4 kN-m/m

Tstress = Fmax =137500 kN/m2 70.99 * Sv

2

Tforce = Tforce =67.496 kN 84.369 kN

Fmax = Tforce Fmax = Tforce

Sv = 1.5 m Sv = 1.1 m

(Ka * σvi - 2c*Ka1/2) * Sv * Sh

M1 + Maϒi + Maqi + αh(ϒ*L*hi2/2) + αh*q*L*hi

(ϒi * hi + q) ± αv*(ϒi * hi + q )+ M3 * 6/L2

In Limiting Case In Limiting Case

(ϒ * hi + q) + M1 * 6/L2

1/6*ϒ*Ka*hi3 + (Ka*q*hi

2/2) - (c*Ka

1/2*hi2)

1/6 * ϒ * Kad *hi3 + (Kad *q * hi

2 / 2)

0.55 * fy

Tstress * π/4 * d2

(Ka * σvi - 2c*Ka1/2) * Sv

2

Take hi = H

Sv = Sh

1.25 * Tstress * π/4 * d2

Kad * σvi * Sv2

Tension FailureStatic Case Seismic Case

Internal Stability

Figure : (a) The Cross-Section of the Soil Nailed Wall with a Planar Failure Surface

(b) The Most Efficient Installation Angle of a Nail

1. The Effect of Upward Nail Inclination to the Stability of Soil Nailed Structure (2004)

By: Erol Güler and Cemal F. Bozkurt

38

Previous work on Topic

(a) (b)

Downward Nailing,

Upward Nailing,

Where,

L = Length of the failure surface,

w = The weight of the soil portion in the left part of the failure surface,

c = Cohesion of the soil,

Φ = Internal friction angle of the soil,

T = Mobilized tension on the nail,

β = The angle of the nail with the failure surface,

H = Height of the wall,

ϒ = Unit weight of the soil.

39

c

(kN/m2)

ϕ

( ° )

Factor of Safety (F.S.1) for nails

inclined 15° below horizontal

Factor of Safety (F.S.2) for nails

inclined 5° above horizontal

%difference

5 20 0.68 0.77 13%

5 30 0.94 1.07 13%

100 10 4.99 5.66 13%

150 10 7.41 8.41 13%

40

Table: Comparison of Factor of Safeties for soil nailed walls with different nail inclinations (ϒsoil = 19 kN/m3)

Depth of excavation (m) Nails inclined (-5°) Nails inclined (15°)

0.0 0 0

2.4 5 5

3.4 5 10

4.4 5 15

5.4 10 20

6.4 15 25

41

Table: Total horizontal lateral displacement at the top of the wall (δh in mm)

2. An Experimental Study on Horizontal and Inclined Soil Nails in Sand (2013)By: Dr. A. K. Verma, Dr. D. R. Bhatt and Vaibhav Javia

Experimental Setup

Tank:-Size: 100 cm X 50 cm X 80 cm (One side wall and both end walls - 5 mm thick mild steel, remaining side of the -10 mm thick Perspex sheet )

Materials

Soil:-Poorly graded sand (SP)

Nails:-Steel bars - 12 mm diameter

42

Figure(a): Horizontal Nailing

Figure(b): Inclined Nailing

(a)

(b)

43

The equation of factor of safety,

44Figure:- Load v/s Settlement

EXPERIMENTAL STUDY

Identification of Soil Grain Size Analysis Specific Gravity Test Relative Density Direct Shear Test

Experimental Set-up for Laboratory Load Test Model Tank Model Wall Facing Preparation of Nails Testing Procedure

45

Grain Size Analysis:

46

From graph: D10 = 0.40, D30 = 0.65, D60 = 1.80Cu = 4.50, CC = 0.094

Type of soil: Poorly Graded Sand (SP)

0.01 0.1 1 100

10

20

30

40

50

60

70

80

90

100Series1

Sieve Dia. (mm)

N (%

)

Sr. No. Properties of Sand Tested Values

1 Coefficient of Uniformity, Cu 4.50

2 Coefficient of Curvature, Cc 0.094

3 Type of Soil Poorly graded sand

4 ρmax 1.89 gm/cm3

5 ρmin 1.49 gm/cm3

6 Specific Gravity, G 2.63

7 Angle of internal friction, ϕ 38.57°

8 Relative Density, Rd 50 %

9 Field Density, ρd 1.67 gm/cm3 47

Experimental Set-up For Laboratory Load Test

Model Tank:• Experiments on model wall were conducted in a rigid steel tank directly rested on

base frame of steel channels which in turn rested on cement concrete floor.

• Test tank size was 100 cm × 50 cm × 80 cm.

• Three sides of tank was built by 5 mm thick mild steel. The remaining fourth side of the tank was built by 10 mm thick Perspex sheet.

• The total inside length of the tank behind the facing was 60 cm.

• Vertical load is applied gradually by hydraulic pressure.

48

49Figure:- Model Tank and Nail Arrangement

Figure :- Play Board

Preparation of Nails:• Steel bars is used Fe 415 and diameter of 12 mm.• Steel bars was cut according to design (L/H) and then threading is done on the end

part of the nails and then front part is grind for easy penetration in sand. • The threading was to facilitate to tighten the nuts on it (nail) to fit with ply board.

Steel bars used were Fe 415 and diameter of 12 mm.

Model Wall Facing:• A 19 mm thick ply board (80 cm high and 48 cm wide) is used as a pre-placed

continuous facing. Circular holes of diameter 16 mm was made on pre-placed continuous facing at the horizontal and vertical spacing.

50Figure :- Nails

Loading Frame

51

Dial Gauge

Proving Ring

40 cm

100 cm

50 cm

20 cm

19 mm

80 cm

48 c

m

Steel Plate

Ply Board

Setup for Load Test

Testing procedure:-• Ply board facing was placed vertically across the tank at a distance of 60 cm from

rear end of tank.

• Initially load test was perform on plate size (48 cm × 8 cm × 2 cm) without nailing condition.

• Initially sand was filled on both sides of facing with same soil and density. Then other side of tank will empty step by step as nailing was done so it could be similar to actual practice.

• Plate was place at 20 cm from the inner side of facing. Two dial gauges will fit diagonally on strip footing to get average deflection.

• The load was apply gradually by means of loading frame. The load was measure by proving ring.

• Ultimate load have been found out using double tangent method.52

Table: List of Experimental Trials

53

Trial No.

Length of nail

L (cm)

Height of sand fill

H (cm)L/H

Horizontal Spacing

Sh (cm)

Vertical Spacing

Sv (cm)

Nail Pattern

Nail Angle

θ (deg.)

1 24 40 0.6 10 10 3 x 4 0°

2 24 40 0.6 10 10 3 x 4 10°

3 24 40 0.6 10 10 3 x 4 15°

4 28 40 0.7 10 10 3 x 4 0°

5 28 40 0.7 10 10 3 x 4 10°

6 28 40 0.7 10 10 3 x 4 15°

7 32 40 0.8 10 10 3 x 4 0°

8 32 40 0.8 10 10 3 x 4 10°

9 32 40 0.8 10 10 3 x 4 15°

RESULTS

54

L/H θ⁰Inclination

Ultimate Load(N)

Settlement(mm)

0.8

0 1700 1.8

10 1900 1.8

15 1300 2

0.7

0 1200 3

10 1350 2.4

15 1150 3.5

0.6

0 700 1.8

10 1100 1.8

15 650 2.2

1. Effect of L/H ratio

From the figure shows that the value of Ultimate Load carrying capacity is maximum for L/H = 0.8 in sand for driven nails.

55

0.6 0.7 0.8600

1100

1600

2100

0⁰ 10⁰ 15⁰L/H Ratio

Ulti

mat

e L

oad

(N)

Fig.: L/H ratio v/s Ultimate Load Curve for Different Nail Inclination

2. Effect of Nail Inclination

From figure shows that the value of ultimate load is maximum for 10 inclination ⁰and it is reduced for the 15 inclination of nail in comparison to horizontal nail.⁰

56

0 5 10 15600

1100

1600

2100

0.8 0.7 0.6Nail Inclination, θ ( )⁰

Ulti

mat

e L

oad

(N)

Fig.: Nail Inclination v/s Ultimate Load Curve for Different L/H ratio

57

CONCLUSION

From the experimental study load carrying capacity is maximum for L/H = 0.8.

For the nail inclination of 10 the load carrying capacity is maximum and settlement ⁰reduces as compared to horizontal nails.

When nail inclination is 15 the load carrying capacity and settlement reduction ⁰reduce as compared to horizontal nails. So, inclined nail up to 10 are more effective ⁰as compared to horizontally inserted nails for same configuration.

58

REFERENCES

• Bowles J. E., “Foundation Analysis and Design”, 5th edition, Tata McGraw Hill Publishing Company, 668.

• BS 8009: 1995 [Strengthened / reinforced soil and other fills]

• C. R. I. Clayton, R. I. Woods, A. J. Bond, J. Milititsky, “Earth Pressure & Earth Retaining Structures”, 3rd Edition, CRC Press, 443.

• D. A. Bruce, “Soil Nailing: Application and Practice – Part 1 & 2”.

• Dhameliya K. B., (2014), “Analysis of Soil Nailed Surface”, M. E. Thesis, GTU.

• Dr. Verma A. K., Dr. Bhatt D. R. & Javia Vaibhav, (2013), “An Experimental Study on Horizontal and Inclined Soil Nails in Sand”, Global Research Analysis, Volume 2, ISSN No 2277-8160.

• Dr. Verma A. K., Patel D. D., Joshi V. H. & Javia V. M., (2015), “A Study of Soil Nailing in Sand”, Indian Geotechnical Journal, 33(3),71-72.

• Erol Güler and Cemal F. Bozkurt, (2004), “The Effect of Upward Nail Inclination to the Stability of Soil Nailed Structure” Geo Trans, ASCE, 2213-2220. 59

• FHWA, (2003), “Geotechnical Engineering Circular No. 7: Soil Nail Walls”, Publication No. FHWA-IF-03-017.

• FHWA, (2003), “Manual for design & Construction Monitoring of Soil Nail Walls”, Publication No. FHWA-IF-03-017.

• G. L. Sivakumar Babu and Singh Vikas Pratap, “Stabilization of vertical cut using soil nailing”, Plaxis Practice.

• IS 1888: 1982 [Bearing capacity of soil by plate load bearing test]

• IS 2720: Part 3: Sec 2: 1980 [Test for Soils - Part 3: Determination of Specific Gravity - Section 2: Fine, Medium and Coarse Grained Soils]

• IS 2720: Part 4: 1985 [Methods of Test for Soils - Part 4: Grain Size Analysis]

• IS 2720: Part 13: 1986 [Methods of Test for Soils - Part 13: Direct Shear Test]

• IS 2720: Part 14: 1983 [Methods of Test for Soils - Part 14: Determination of Density Index (Relative Density) of Cohesionless Soils]

• K. Premalatha, M. Muthu Kumar, D. Mohan Babu, (2009), “Analysis and Design of Nailed Soil Wall - A Case Study”, IGC, Guntur, 574-577.

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• K. Premalatha, M. Muthukumar and A. Amala Raju Arul, (2010), “Simplified Method of Design of Nailed Soil wall”, GeoFlorida 2010: Advances in Analysis, Modeling & Design (GSP 199), ASCE, 2271-2280.

• Mittal S., Gupta R. P. and Mittal N., (2005), “Housing Construction on Inclined Cuts”, Asian Journal of Civil Engineering (Building and Housing) Vol. 6, No. 4, 331-346.

• Patra C. P. and Basudhar P. K., (2001), “Nailed Soil Structure: An Overview”, Indian Geotechnical Journal, 31(4), 331-367.

• Shivakumar Babu, “Soil Reinforcement and Geosynthetics”, Universities Press, 118-134.

• Swami Saran, “Reinforced Soil and its Engineering Applications”, 2nd Edition, I. K. International Publication House Pvt. Ltd., 261.

• T. Aishwarya and K. Ilamparuthi, (2013), “Study on Soil Nailing Based on Parametric Analysis”, Indian Geotechnical Conference December 22-24, Roorkee.

• Wei Yiqing, (2013), “ Development of Equivalent Surcharge Loads for the Design of Soil Nailed Segment of MSE/Soil Nail Hybrid Retaining Walls Based on Results from Full-Scale Wall Instrumentation and Finite Element Analysis”, Texas Tech University.

• Wikipedia, the free encyclopedia http://en.wikipedia.org/wiki/soil_nailing.61

Thank You

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