The Effect of Jet Grouting on Enhancing the Lateral Behavior of Piled Raft Foundation in Soft Clay (Numerical Investigation)

Soft clay soils cannot usually support large lateral loads, so clay soils must be improved to increase lateral resistance. The jet grouting method is one of the methods used to improve weak soils. In this paper, a series of 3D finite element studies were conducted using Plaxis 3D software to investigate the lateral behavior of piled rafts in improved soft clay utilizing the jet grouting method. Parametric models were analyzed to explore the influence of the width, depth, and location of the grouted clay on the lateral resistance. Additionally, the effect of vertical loads on the lateral behavior of piled rafts in grouted clay was also investigated. The numerical results indicate that the lateral resistance increases by increasing the dimensions of the jet grouting beneath and around the piled raft. Typical increases in lateral resistance are 11.2%, 65%, 177%, and 35% for applying jet grouting beside the raft, below the raft, below and around the raft, and grouted strips parallel to lateral loads, respectively. It was also found that increasing the depth of grouted clay enhances lateral resistance up to a certain depth, about 6 to 10 times the pile diameter (6 to 10D). In contrast, the improvement ratio is limited beyond 10D. Furthermore, the results demonstrate that the presence of vertical loads has a significant impact on sideward resistance

Utilization of Marble Dust for Improving The Geotechnic Characteristics Of Collapsible Soil

An environment friendly and cost effective factor of collapsible soil stabilization with the help of industrial waste has been widely adopted in this research. Buildings which are constructed on collapsible soils are subjected to large deformations and shear failure. Collapsible soil can be broadly categorized as those soils susceptible to a large reduction in volume upon wetting. The mechanism usually involved in rapid volume reduction entails breaking of bonds at coarse particle contacts by weakening of fine grained materials brought there by surface tension in evaporating water. This research presents the effects of using marble dust on the geotechnical properties of Collapsible soil as a new stabilizing technique. A series of experimental tests are carried for samples of collapsing soil with and without stabilization using marble dust for dry and soaked conditions. The collapsible soil was mixed with marble dust at different contents of (0, 10, 20, 30%,40% and 50%). The results indicated that, The optimum water content decreases by 20.67% at marble content of 50%, liquid limit decreses by35.41% at marble content of 50% and frictional angle for soaked soil decreases by 66.09% at marble content of 50% while un soaked soil decreases by54.68% at marble content of 50%. The maximum dry density increases 5.91% at marble content of 50% and cohesion for soaked increases 314.2% at marble content of 50% while un soaked soil increases 206.7% at marble content of 50%. It has been found that the adopted marble has a good effect in controlling the collapsing potential which is reduced by as much as 64.32% at marble content of 30%

Behaviour of Laterally Anchored Retaining System in Loose Sand Soil

One of the earliest earth retention technologies used in civil engineering projects is sheet pile walls. Therefore, in this work, a numerical analysis using Plaxis 2D was performed to investigate the behaviour of laterally anchored retaining system in sandy soil, focusing on the anchor force, lateral displacement, and maximum bending moment. The effects of anchor location and number on wall and soil deformations were investigated for various wall heights. When anchored-sheet-piles were used instead of cantilever sheet piles, the results showed a significant reduction in both wall deformation and bending moment specially at high dredging levels. In addition, while having numerous anchor levels is the most approach to minimize wall and soil deformations. Also, the findings revealed that adopting the one-anchored sheet pile wall can greatly decrease the maximum wall displacement by about and 59.16%; which occurs at 0.4H; as well as reduce the maximum bending moment by about 85.63%; which occurs at 0.5H, comparing with the cantilever sheet pile wall at dredging depth (H) = 5m. At a deeper dredging depth (H=9m), the maximum lateral displacement and maximum of wall were reduced by 88 %, and 86 %, respectively. Also, at H= 9m, using the second level of anchors can also reduce the maximum bending moment on the wall by more than 83.55 %

Properties of Cement Composites Utilizing of Bentonite: A Review

The use of bentonite clay slurries in civil and geotechnical engineering dates back to Veder\u27s pioneering work in 1953. Since then, bentonite has been used for various applications such as the construction of bored piles and diaphragm walls. Plastic concrete walls also require sufficient strength and modulus to adapt to the surrounding environment, and the characteristics and different forms of bentonite commercially available were reviewed in this paper.This paper reviews the properties and applications of bentonite, including its use in cement-bentonite composites for remedial cut-off wall construction. Cement-bentonite grouts offer advantages over bentonite grouts in terms of ease of use and adjustability of strength.Cement-bentonite composites were found to be promising materials for remedial cut-off wall construction due to their ability to meet requirements for strength, stiffness, and permeability. By regulating the mix proportions, the strength of the set grout can be adjusted to match that of the surrounding ground. Cement-bentonite grouts also offer advantages over traditional bentonite grouts, as they are easier to use, offer a longer working period before setting, and can be forgiving if the user deviates from the design formula or the mixing technique. This paper provides useful information for those working with bentonite and cement-bentonite composites in civil and geotechnical engineering applications

Properties of Cement Composites Utilizing of Bentonite: A Review

The use of bentonite clay slurries in civil and geotechnical engineering dates back to Veder\u27s pioneering work in 1953. Since then, bentonite has been used for various applications such as the construction of bored piles and diaphragm walls. Plastic concrete walls also require sufficient strength and modulus to adapt to the surrounding environment, and the characteristics and different forms of bentonite commercially available were reviewed in this paper.This paper reviews the properties and applications of bentonite, including its use in cement-bentonite composites for remedial cut-off wall construction. Cement-bentonite grouts offer advantages over bentonite grouts in terms of ease of use and adjustability of strength.Cement-bentonite composites were found to be promising materials for remedial cut-off wall construction due to their ability to meet requirements for strength, stiffness, and permeability. By regulating the mix proportions, the strength of the set grout can be adjusted to match that of the surrounding ground. Cement-bentonite grouts also offer advantages over traditional bentonite grouts, as they are easier to use, offer a longer working period before setting, and can be forgiving if the user deviates from the design formula or the mixing technique. This paper provides useful information for those working with bentonite and cement-bentonite composites in civil and geotechnical engineering applications

Improvement of Expansive Soil by Using Micro Silica Fume

Expansive soil shows frequent volume changes with the changes in the moisture content, causing severe problems to the civil engineering structures. Consequently, the measurements of swelling properties including free swell index and swelling pressure are extremely important. Several attempts are being made all over the world to control the swell-shrink behavior of expansive soils. Many researches have investigated how to overcome the problems of such soils by means of using different additives such as cement, lime, steel fibers, stone dust and fly ash. This study is directed towards the improvement of expansive soil with a new, inexpensive and environmentally friendly additive. In this study, the effect of using micro silica fume to stabilize the soil was investigated through a laboratory study. Test results showed that, the micro silica fume can considerably decrease the free swell index value by 69% at 25% micro silica fume content. Also, the swelling pressure is reduced from 410 kN/m2 to nearly 330 kN/m2 and 302 kN/m2 at micro silica fume content of 5% and 25%, respectively. This demonstrates the effectiveness of the proposed addition in the expansive soils improvement. This improvement technique can be used in different civil engineering construction projects including slope stabilization and road embankments