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In view of the fact that the anti sliding effect analysis of the current anchor cable and anti slide pile structure is not yet complete, research on the synergy mechanism of adjacent pile-anchor composite structures under traffic load is carried out. Firstly, a free vibration analysis for the slope dynamic model is carried out by using a three-dime...
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In this paper, a shear deformation theory for the bending and free vibration analysis of functionally graded plates is developed. The number of unknowns and governing equations of the present theory is reduced, and hence makes it simple to use. The present plate theory approach accounts for both transverse shear and normal deformations and satisfie...
Citations
... However, conventional single piles or anchors may have significant pile bending moments, be insufficiently secured, have a restricted range of use, or be costly, furthermore, having the capacity to enhance the anti-slide pile's cantilever condition for improved resistance to landslide thrust while keeping the advantages of a more beneficial stress distribution [15][16][17][18]. The standard structural form has difficulties when treating big slopes, which the combined structure can more successfully address [19,20]. Furthermore, the dynamic response of slopes stabilized by pile-anchor systems has not been well understood till now. ...
Pile–anchor reinforcement is among the most popular and efficient slope-reinforcement techniques. However, little is known about the behavior of pile–anchor structures under the influence of seismic loads used for slope reinforcement. Therefore, it is crucial to evaluate reinforcement performance under seismic loads. This paper presents the numerical response of a slope strengthened by a pile–anchor structure system with different anchor angles. The best reinforcement angle is determined based on the control of slope displacements at various points and the safety factor of slopes under different conditions. A maximum safety factor of 1.179 and minimum displacement of 0.654 m occurred with an anchor angle of 15°. The study results showed that the pile–anchor reinforcement with an anchor angle of 15° performed best for slope stability.
... Numerical simulations offer an economical and reliable approach for analyzing the behaviors of reinforced slopes [15][16][17], including the finite element method (FEM), the finite difference method (FDM), mesh-free methods [18][19][20][21][22], and artificial intelligence methods [23][24][25][26][27][28][29][30][31][32]. Among these methods, the FEM and the FDM are the most widely used. ...
In earthquake-prone areas, pile-anchor structures are widely employed for slope reinforcement due to their reliable performance. Current research has primarily focused on static and quasi-static analyses of slopes reinforced by using pile-anchor structures, with limited investigation into their dynamic response. In this work, the finite element method (FEM) is used to study the dynamic behavior of a pile-anchor slope system, and the extended finite element method (XFEM) is used to simulate the progressive failure processes of piles. Three different reinforcement schemes, which include no support, pile support, and pile-anchor support, are considered to examine the performance of the pile-anchor structure. The simulation results suggest that the pile-anchor structure displays a reduction of 39.6% and 40.6% in the maximum shear force and bending moment of the piles, respectively, compared to the pile structure. The XFEM is utilized to model the progressive failure process of the piles subjected to seismic loading. We find that crack initiation in the pile body near the slip surface, for both the pile supported and the pile-anchor supported conditions, occurs when the peak ground acceleration arrives. Crack growth in the piles completes in a very short period, with two distinct increments of crack area observed. The first increment occurs when the peak ground acceleration arrives and is significantly larger than the second increment. Consequently, for the seismic design of piles, it is necessary to strengthen the pile body around slip surfaces. The novelty of this paper is that we realize the simulation of crack initiation and propagation in piles subjected to seismic loading.
... Gischig et al. [13] obtained that the amplification coefficient of slope frequency is highly sensitive to the change of cracks by using the numerical simulation method. For other retaining structures, such as the pile-anchor structure, micro-pile and so on, the time-frequency domain analysis based on slope acceleration has also become a means of analyzing slope dynamic response [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29]. ...
In order to study the instability development process of the slope reinforced by anti-slide piles under earthquake conditions, the dynamic response characteristics of the slope are usually taken as the main characteristics, and the model test and numerical simulation are the main research methods. In this paper, a shaking table model test is designed and completed to investigate the influence of anti-slide piles with different initial damage on the failure mode of high and steep slope under earthquake conditions. The changes in velocity, strain and natural frequency during slope vibration are tested in combination with cloud maps when sinusoidal waves of different accelerations with a peak value of 5 Hz are applied. Thus, the differences of slope failure development process and dynamic response characteristics are obtained. The experimental results show that the anti-slide pile with different initial damage has obvious influence on the slope instability process. Under the condition of good anti-slide pile quality, the failure development of the slope behind the pile is limited to soil sliding on top of the slope, slope sliding and overburden sliding; the front slope foot of pile mainly forms shear belt and local sliding. With the decrease in the initial mass of the anti-slide pile, the slope failure develops into topsoil sliding, slope sliding and deep integral sliding; analogously, the failure of the slope in front of the pile develops into a whole slip along the slip belt. The natural frequency cloud map can directly reflect the damage location of the slope, and the frequency change rate is positively correlated with the cumulative shear strain. It shows that the macro-failure characteristics of the model slope change well when the natural frequency is used as the sensitive index to measure the influence of vibration on the model slope. The threshold value of the natural frequency change rate can distinguish different development stages of the slope; 1% is the threshold value of stage II, and 1.5% is the threshold value of stage III.
To provide reference for the design and construction of anchoring measures in slope reinforcement and treatment projects, this article presents the on-site monitoring and analysis of the stress changes in anchor rods and anchor cables in a high-level layered rock slope of a deep excavation highway. Anchor rods and anchor cables are widely used reinforcement measures in slope reinforcement due to their simplicity and economy. In this article, we took the layered rock slope of a deep excavation highway as the monitoring object and installed monitoring equipment on slopes of different levels. Based on the monitoring data of slope anchor rods and anchor cables, the rationality of slope reinforcement and treatment measures was analyzed. This study shows that active support anchor cables have better reinforcement effects than the passive protection of anchor rods. The approximate position of the potential slip surface in the slope mass can be inferred according to the monitoring of slope anchor stress, which can guide a slope reinforcement and treatment project. Finally, FLAC3D V6.0 was used for numerical simulation analysis, which showed that the slope was in a stable state under the support of anchor rods and anchor cables.
The construction process is often different from the ideal process in the design scheme. To investigate the effect of construction sequence on the force of the pile-anchor support structure in foundation pit, the internal force of the pile-anchor support structure under two different construction sequences was monitored and analyzed based on a deep foundation pit project in Lanzhou, China, and the internal force change law of the pile-anchor support structure under different construction sequences was obtained and further verified and analyzed using finite element method. The results show that there are many differences in the internal forces of anchor cables under different construction sequences, and the time to apply prestress to anchor cables has an important influence on the internal force distribution of the support piles. When the first anchor cable is prestressed and the second and third anchor cables are not prestressed, the pile is actively stressed and the pile moment is distributed in an "S" shape, with the negative moment at the top and the positive moment at the bottom. When the upper three anchor cables are not prestressed at the same time, the support pile is in a passive stress state and the pile bending moment is negative. If the anchor cables are not tensioned in time after construction, the excavation will cause irreversible changes in the bearing state of the support piles, and the maximum displacement of the support piles will increase about 26% and the maximum bending moment of the support piles will increase about 42.8% compared with the normal working condition, which is not conducive to the safety of the foundation pit. Therefore, the principle of "soil should be excavated in layers and anchor cables should be tensioned in time" should be strictly followed during construction.
