Shaking Table Test on the Seismic Responses of a Slope Reinforced by Prestressed Anchor Cables and Double‐Row Antisliding Piles

Abstract

The combined retaining structure has gradually received considerable attention in the slope engineering, due to its good reinforcement effects. However, most of the published research studies were focused on the seismic responses of the single-formal supporting structure only. The investigations of dynamic responses of the combined retaining structures are scarce, and the current seismic design is conducted mainly based on experiences. In this work, a series of large-scale shaking table tests were conducted to investigate the seismic responses of the combined retaining structures (i.e., prestressed anchor cables and double-row antisliding piles) and the reinforced slope under seismic excitations, including amplification effect of internal and surface acceleration of the reinforced slope, distribution and change of prestress of the anchor cable, dynamic response of soil pressure behind the antislide pile, and horizontal displacement of the reinforced slope surface. Test results show that, supported by the reinforcement of composite support system, the slope with the multilayer weak sliding surface can experience strong ground motion of 0.9 g. The load of the antisliding pile has reached 80% of its bearing capacity, and the load of the anchor cable has reached 75.0% of its bearing capacity. When the seismic intensity reaches 0.5 g, the slope surface has an obvious downward trend, which will make the corresponding soil pressure suddenly increase after the antislide pile. At the potential sliding zone, the axial force of the anchor cable will increase suddenly under the action of earthquake; after the earthquake, the initial prestress of the anchor cable will be lost, with the loss range of 17.0%∼23.0%. These test results would provide an important reference for the further study of the seismic performance of such composite support structure.

Superimposed Stress Calculation of Soil Underlying Anchor Beam considering Anisotropy and Strength Nonhomogeneity

“…Equation (16) illustrates the relationship between the cohesion of soil in the horizontal and vertical directions. Equation (17) shows the cohesive force of the saturated and undrained clay soil; c Ψ was influenced by the anisotropy coefficient of soil. Therefore, assuming that the cables were subjected to a prestress of 500 kPa, the displacement and stress responses of the slope were obtained.…”

“…Yang et al [12] studied the variation of tension in prestressed anchor cables based on field monitoring; they summarized the variation features of anchor tension considering the install positions on a single anchor pile, anchoring strata, and locations on the plane of the foundation pit. Wu et al [17] conducted shaking table tests to investigate the seismic response of a slope reinforced by prestressed anchor cables and double-row antisliding piles, and they revealed that the reinforced slope had good overall stability. Sun et al [18] proposed a large deformation anchor cable support system and used 3DEC software and a series of field tests to study the effect of applying an NPR anchor cable support system, showing that the NPR anchor cable support system achieved good results in tunnel engineering.…”

Seismic Response Evaluation of High-Steep Slopes Supported by Anti-Slide Piles with Different Initial Damage Based on Shaking Table Test

“…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 ].…”