A Review of Soil Nailing

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International Journal of Advance Engineering and Research Development Scientific Journal of Impact Factor (SJIF): 4.72 Special Issue SIEICON-2017,April -2017 e-ISSN : 2348-4470 p-ISSN : 2348-6406

A Review Of Soil Nailing

Jadeja Rajveer1, Savani Brijesh2, Makawana Hardik3, Kalsariya Dinesh4, Maulik Kansagara5 1Civil Department, Sigma institute of engineering 2 Civil Department, Sigma institute of engineering 3 Civil Department, Sigma institute of engineering 4 Civil Department, Sigma institute of engineering 5 Assistant professor, Civil Department, Sigma institute of engineering

Abstract: Foundation failure can cause the building to fall down. Repair of defects in foundations are most difficult and very costly, so it is most significant to understand the types of foundation failure to avoid them by taking required steps before construction starts. The main aim of this research is to bring soil stability in area where landslides might be a problem by inserting carbon rods in place of steel reinforcement bars in yellow type soil. Carbon fiber reinforced polymer, carbon fiber reinforced plastic or carbon fiber reinforced thermoplastic (CFRP, CRP, CFRTP or often simply carbon fiber, or even carbon), is an extremely strong and light fiber-reinforced plastic which contains carbon fibers.

Keywords- Soil, Carbon Anchor, Density

I. INTRODUCTION. Soil is called the "Skin of the Earth" and interface with its lithosphere, hydrosphere, atmosphere, and biosphere. It is a mixture of minerals, organic matter, gases, liquids, and limitless organisms that together maintain life on Earth. Soil consists of a solid phase of raw materials and organic matter, as well as a porous phase that hold gases and water. Accordingly, soils are often treating as a three-state system of solids, liquid, and gas.

Soil nailing is a construction method that can be used as a remedial measure to treat unstable natural soil slopes or as a construction technique that allows the safe over-steepening of new or presented soil slopes. The technique involves the insertion of relatively slender reinforcing elements into the slope – often general purpose reinforce bars though proprietary solid or hollow-system bars are also available. Solid bars are usually installed into pre-drilled holes and then grouted into place using a separate grout line, whereas hollow bars may be drilled and grouted simultaneously by the use of a sacrificial drill bit and by pumping grout down the hollow bar as drilling progress. The purpose is to provide updated, state-of-the-practice information for selecting, designing, and construct soil nail walls for road way project. The information contained herein is aimed at producing secure and cost-effective soil nail designs for road way projects, and to help owners to recognize and manage the risks associated with soil nail wall projects. It focuses slowly on soil nail systems providing long-term support of excavation of a permanent structure. It does not specially address the use of soil nails as temporary structures for providing temporary support of excavation or to become constant landslide.

The purpose is to provide updated, state-of-the-practice information for selecting, designing, and constructing soil nail walls for road way project. The information contained here is aimed at producing secure and cost-effective soil nail designs for roadway projects, and to help owners to identify and manage the risks connected with soil nail wall projects. It focuses slowly on soil nail systems providing long-term support of excavation of a permanent structure. It does not specially address the use of soil nails as temporary structures for providing temporary support of excavation or to become stable landslides.

II. LITERATURE REVIEW Parametric assessment of soil-nailing retaining structures in cohesive and cohesionless soils [5]

International Journal of Advance Engineering and Research Development (IJAERD) Special Issue SIEICON-2017, April -2017,e-ISSN: 2348 - 4470 , print-ISSN:2348-6406

In this study, the significant influence of the shear strength of soil-nail cut and of the amount of surcharge on the structural behavior of soil-nailing retaining walls is described. „Plaxis‟ finite- element modeling software is very normally used for numerical simulations. There are difficulty associated with accurately modeling behaviors of these structures in both cohesive and cohesion less soils. The results show that the soil‟s physical properties and surcharge directly influence the soil- nailing structures. One more important conclusion is that a soil-nailing structure consisting of nails and tiebacks can be considered a good alternative to improve the safety of excavation walls due to its satisfactory behaviour in the numerical simulations.

NUMERICAL MODELLING OF SOIL NAILS IN LOOSE FILL SLOPE UNDER SURCHARGE LOADING [6]

In this paper, a plane–strain numerical model has been developed to mimic a nailed loose fill slope under surcharge loading. The model has been used to back-analyse a field test that was conducted to inspect the behavior of soil nails in loose fill slopes under surcharge loading. Incremental elasto- plastic analyses coupled with pore water diffusion have been perform to study the internal deformation, water content redistribution in the soil, and the performance of the soil nails during and after the application of surcharge loading. The model parameters describing the mechanical and hydraulic properties of the nailed slope were obtained from field or laboratory tests. Different modeling techniques and boundary conditions for mimicking soil–nail interaction in loose fill material have been examined. Comparisons between numerical predictions and field measurements demonstrate that a new interfacial model, denoted as the embedded bond–slip interface model, is more suitable for mimicking the interfacial behavior. Despite the simplicity of the numerical model, the predicted responses are in close agreement with the field test results, in particular the mobilization and distribution of nail forces in response to surcharge loading. Both the numerical and the field test results suggest that soil nails are capable of increasing the overall stability of a loose fill slope for the loading conditions considered in this study. The increase in confining stress along the soil nails near the surcharge area is central to the overall stabilizing mechanism. On the contrary, the nail forces mobilized near the nail heads are much smaller, indicating that the beneficial effect of having a structural grillage system at the slope face is limited for the range of surcharge pressures considered in this study. Parametric assessment of soil-nailing - a review Discovery [2] Soil nailing is one of the newest techniques of stabilizing the steep slopes. There are various methods which are used to analyze the soil nailing behavior in several cases. Software are available for simulation and analysis of the soil nailing condition like ABAQUS, Slide 6, PLAXIS are the most common software used by researchers and designers. Although, design concepts on which these software based influence the analysis and design of soil nailing. This paper presents the effects of influencing factor which is applied for soil nailing system. Different methods and models used by various software to design a soil nailing system are also discussed. On the basis of review a new design method known as embedded bond-slip model was found more convenient and realistic as compared to other conventional methods. NUMERICAL STUDY ON THE OPTIMUM LAYOUT OF SOIL–NAILED SLOPES [3]

This paper presents a numerical study on the optimum layout of soil nails to stabilize slopes. Result of nail orientation and geometric layout on the overall stability of soil–nailed slopes with various geometric conditions is investigated using the non-linear finite element approach. Stability of soil– nailed slopes is evaluated in terms of factor of safety. The optimal nail orientation for slope angle of

International Journal of Advance Engineering and Research Development (IJAERD) Special Issue SIEICON-2017, April -2017,e-ISSN: 2348 - 4470 , print-ISSN:2348-6406

90°, 80°, 70°, 60°, 50°, and 40° are 0°, 8°, 16°, 23°, 30°, and 40°, respectively, for soil–nailed slopes with a horizontal back slope. The optimal nail orientation in relation to the horizontal plane increases with a decrease in the gradient of soil–nailed slopes and it increases with an increase in the gradient of back slopes. Nail length at the lower 1/3 part of the slope is more important to the overall stability of slopes than those at other parts, especially for soil–nailed walls. Effect of arrangement of vertical spacing of nails on the stability of soil–nailed slopes is not important if number and amount of nails used in slopes remain unaffected.

Analysis of shallow instabilities in soil slopes reinforced with nailed steel wire meshes [1]

In this paper on soil nailing the limit equilibrium technique is developed for the analysis of shallow instabilities in soil slopes reinforced with nailed steel wire meshes. Shallow instabilities are associated to ground weathering or shallow water flow affecting a moderate depth, about 10–20% of the slope height. These effects are considered in the analysis as a reduction of the soil strength. The reinforcing mesh is assumed to act as a distributed pressure on the slope surface. The aim is to establish the value of the normal pressure needed to reach a given safety factor against shallow instability. The proposed method is presented first for an infinite slope, leading to a closed form solution. If the height of the slope has to be considered as finite, a second analysis is developed dividing the unstable layer of soil in finite blocks. The result is given as a correction factor to be applied to the infinite slope solution. An application example is used to illustrate the design of practical cases.

The results of the limit analysis are comparing with finite element calculations. The stabilization effect achieved by the wire mesh is evaluated as the increase of the possible reduction of the soil strength before the slope failure.

In-plane stiffening techniques with nail plates or CFRP strips for timber floors in historical masonry buildings [4] The paper investigates two strengthening techniques for timber floors in historical masonry buildings. These alternative solutions may be used to enhance in-plane stiffness and strength of existing wooden floors. According to the first technique, nail plates are utilized to connect adjacent timber boards, while diagonal carbon fiber (CFRP) strips glued to timber boarding are considered in the second solution. Four full scale stiffened floor samples, which were designed using specific relationships to calculate in-plane stiffness and resistance, were tested under in-plane cyclic loading. Test results showed an enhanced stiffness for strengthened floors which is 40–50 times higher than that of the original wooden floor and close to the value calculated employing the proposed design expressions. To study how the use of the analyze stiffening solutions affects the seismic performance of masonry buildings, nonlinear static analyses were carried out on a typical historical masonry building with wooded floors under earthquake loading. In particular, the response of the building with original floors was compared with that of the structure with strengthened floors. The numerical results confirmed that the stiffness of the reinforced floors is adequate to guarantee satisfactory structural integrity for the whole building as damage was establish to be mainly located in shear walls, while walls perpendicular to earthquake loading remained almost undamaged. The following table shows the literature review done by the researce in the field of soil nailing.

International Journal of Advance Engineering and Research Development (IJAERD) Special Issue SIEICON-2017, April -2017,e-ISSN: 2348 - 4470 , print-ISSN:2348-6406

Table 1: Summary of literature review

III. CONCLUSION From the above literature review it seems that soil nailing has not been carried out for all the types of soil. The table shows that lot of research is remaining in the field of soil nailing which will give strength to soil and will anchor accordingly to the needs. So this project will define the usage of carbon rods for yellow soil as soil anchor.

REFERENCES

[1]Bhimsen; “Parametric assessment of soil-nailing - a review Discovery”, 2015, 42(191), 1-5 Publication History; Student, Dept. of Civil Engineering, Motilal Nehru National Institute of Technology Allahabad, Allahabad, India Published: 9 October 2015. [2]Chia-Cheng Fan, , Jiun-Hung Luo; “Numerical study on the optimum layout of soil–nailed slopes”, Original Research Article Computers and Geotechnics, Volume 35, Issue 4, July 2008, Pages 585-599. [3]Natalino Gattesco, Lorenzo Macorini; “In-plane stiffening techniques with nail plates or CFRP strips for timber floors in historical masonry buildings”, Pages 64-76 , Volume 58, 15 May 2014,

International Journal of Advance Engineering and Research Development (IJAERD) Special Issue SIEICON-2017, April -2017,e-ISSN: 2348 - 4470 , print-ISSN:2348-6406

[4]Soheil Ghareh; “Parametric assessment of soil-nailing retaining structures in cohesive and cohesionless soils”; September 2015, Pages 341-351; Department of Civil Engineering, Payame Noor University, 29 May 2015. [5]Y.D. Zhou , C.Y. Cheuk , L.G. Tham; “Numerical modelling of soil nails in loose fill slope under surcharge loading”; Volume 36, Issue 5, June 2009, Pages 837-850; Department of Civil Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong, China; 20 January 2009. [6]Almudena Da Costa, Cesar Sagaseta “Analysis of shallow instabilities in soil slopes reinforced with nailed steel wire meshes”, Pages 53-61, Department of Ground Engineering and Materials Science, University of Cantabria Avda, Spain; 27 February 2010 Volume 113, Issues 1–4, 12 May 2010.