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Retaining structures
Published in Rodrigo Salgado, The Engineering of Foundations, Slopes and Retaining Structures, 2022
Mechanically stabilized walls are commonly built of a suitable soil (traditionally sandy soil with less than 15% fines) reinforced typically using strips, sheets, or grids made of extensible (polymers) or inextensible (mild steel or aluminum) materials. Geotextiles, shown in Figure 16.9, are a form of geosynthetic made of polymer or fiberglass fibers. They may be manufactured in much the same way as traditional textiles in weaving machines,7 in which case they are called woven geotextiles, or by processes leading to a random fiber arrangement, in which case they are called nonwoven geotextiles. For soil reinforcement, woven geotextiles are typically used because they have higher tensile resistance. Geogrids, shown in Figure 16.9, are plastic grids, with apertures of a centimeter or more in width, made either by punching holes in plastic sheets and stretching them or by weaving. Geogrids can be either uniaxial or biaxial (that is, “strong” in one or two directions). Uniaxial geogrids are usually more appropriate for soil reinforcement applications in which the direction where reinforcement is needed is perpendicular to the wall.
Deformation classifying and reconstructing method for smart Geogrid integrated with fiber Bragg grating sensors
Published in Airong Chen, Xin Ruan, Dan M. Frangopol, Life-Cycle Civil Engineering: Innovation, Theory and Practice, 2021
Z.F. Wang, J. Wang*, J.Q. Zhang, C.B. Tian, Q.M. Sui, Y.N. Dong, L. Jia, X.M. Liang
Geogrids are extensively used in the geoengineering as reinforcements to stabilize the soil structures. Recently, attentions have been paid to the smart Geogrids which is formed by integrating the geogrid with different kinds of sensors. These geosythenitics with sensor arrays have the self-sensing functionality when being utilized as reinforcements. Owing to the advantages, including fibrous nature, immunity to electromagnetic interference, etc., fiber optic sensors have been utilized to fabricate the smart geosythenitics. Most of the existing studies employed distributed optic fiber sensor to fabricate the smart geosythenitics such as geotextiles or geogrid for the monitoring of the strains. Apart from that, a geotextile fabric embedded fiber Bragg gratings (FBGs), which was named as “Geodetect” system, was designed to measure strains, and implemented in several practical civil engineering.
Application
Published in Andrew Braham, Sadie Casillas, Fundamentals of Sustainability in Civil Engineering, 2020
As more retaining walls were designed and installed, a new concept was developed that used the mass of the soil behind the wall to maintain the shape of the soil mass. This concept is referred to as a mechanical stabilized earth (MSE) wall. MSE walls are built in layers, where 1–2 foot lifts of select backfill are placed and compacted, and strips are laid on the soil. These strips can be made out of metal, geogrid, or geotextile. A geogrid is generally made out of a rigid plastic (i.e. polyester) that is arranged in a grid pattern which allows for soil or aggregate interlock within the grid while still increasing the tensile strength of the soil or aggregate. A geotextile is more of a fabric that not only provides tensile strength from friction between the soil and fabric, but can also filter and drain water, or separate different materials without fear of contamination. Both geogrids and geotextiles fall within the geosynthetic family of materials.
Role of Geogrid reinforcement and its diverse applications in the geotechnical engineering and allied fields: a-state-of-the-art review
Published in Australian Journal of Civil Engineering, 2023
Kiran Prakash K, Deendayal Rathod, Kasinathan Muthukkumaran
Engineering soil is weak in tension. After extensive research, we deduced that the incorporation of a tensile material into engineered soil would overcome the weakness of the soil. Geogrid is a tensile material, and owing to its economy, ease of construction, and environmentally friendly nature, they are abundantly used to reinforce poor soil. The performance and load-carrying capacity of the soil-geogrid composite system is enhanced by the interaction between soil and geogrid reinforcement with a high stiffness ratio. The stiffness difference between soil and geogrid has an important effect on shear stress mobilisation along the geogrid, which increases the shear strength of reinforced soil, popularly known as the stiffening effect (Halder and Chakraborty 2019; Tutumluer, Huang, and Bian 2012). The tensile force of the geogrid can be increased even further by using prestressing geogrid concepts (Lackner, Bergado, and Semprich 2013). The aperture size, mechanical properties of the geosynthetic product, and soil used also positively affect increased load-carrying capacity and reduced irrecoverable deformation.
Behavior of Concrete Slabs Reinforced by Different Geosynthetic Materials
Published in HBRC Journal, 2022
Ahmed M. El-Hanafy, Samiha E. Alharthy, Ahmed M. Anwar
Geogrids are one of the polymeric materials classified under geosynthetics materials consisting of parallel arrangements of connected tensile ribs with openings of satisfactory measure to permit strike-through of surrounding geotechnical material [1]. Geogrids have been typically utilized in earthen structures such as pavements, embankments and shallow foundations. The essential work of geogrids is to supply fortification to earth structures. While unbound granular geo-materials ordinarily cannot withstand tension, the use of the geogrid reinforcement gives resistance to particle movement [2]. Geosynthetics have widely been used in geotechnical applications. They are utilized as reinforcement elements to achieve stabilization of soil. Geogrids have been successfully utilized to improve delicate subgrades and give a development stage over them [3,4]. Khadaii et al. studied using geogrids as interlayers to relieve intelligent cracking in black top overlays of jointed plain concrete (JPC).
Anti-Seismic Retrofitting Techniques for Vernacular Adobe Buildings in Colombia: A Proposed Framework for Developing and Assessing Sustainable and Appropriate Interventions
Published in International Journal of Architectural Heritage, 2022
F. De Filippi, R. Pennacchio, S. Torres, L. Restuccia
E.Materials durability. The high durability of geogrids and rib-lath grids could be ensured considering how synthetic nylon and galvanized steel (their main materials respectively) have shown high resistance to environmental or chemical agents. According to Fannin, Quinteros, and Vaslestad (2013), geogrids after 30 years of proper use had not reported important degradations. Galvanized steel used for earth-retaining wall technologies has already proven its resistance in a soil environment. Nevertheless, both retrofitting strategies require to be covered with earthen or sand-lime plasters, in order to ensure both structural and protective functions; such plaster requires periodical maintenance. Wood biological and weathering protection can guarantee the high durability of this material when used for timber grids and corner braces reinforcements. Its compatibility with earth material can be considered high when water vapor exchange is assured, even if wood elements are entirely embedded in soil. Finally, due to the use of the same material as the reinforced structure, buttresses’ durability can be considered the same as the adobe building’s nominal design life.