Shear Effects on the Anchorage Interfaces and Seismic Responses of a Rock Slope Containing a Weak Layer under Seismic Action

Zhe Long,Zhi-Xin Yan,Chun-Bo Liu

doi:10.1155/2020/1424167

Zhe Long, Zhi-Xin Yan + Show 1 more

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https://doi.org/10.1155/2020/1424167

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Abstract

The shear effects on the anchorage interfaces under seismic action is a key problem requiring urgent investigation in the field of rock and soil anchorages. In this paper, the model of rock slope with a weak layer was constructed by pouring, and the large-scale shaking table model test was completed. The shear strain on the anchorage interfaces and the acceleration of the slope were collected using built measurement systems. The shear effects on the two anchorage interfaces (a bolt-grout interface and a grout-rock interface) and seismic responses of the slope under seismic action were investigated. The distribution laws of the shear stress on the two anchorage interfaces along the axial direction of the bolt under seismic action were gained. The variations of the peak acceleration amplification coefficient on the slope surface, the magnitude, and the growth rate of peak shear stress on the anchorage interfaces under seismic action with different excitation directions and intensities were obtained. Furthermore, the positive relationship between the shear effect on the anchorage interfaces and the seismic response of slope was revealed. This study provides support for theoretical research, numerical simulation analysis, and aseismic design of rock and soil anchorages under dynamic conditions.

Highlights

IntroductionAs a common method for supporting rock and soil masses, is extensively used in projects and plays a critical role in major projects due to its unique advantages such as delicate structures, ease of construction, low cost, and high performance; research into mechanisms used for anchoring slopes under seismic action lags far behind engineering practice, so it is necessary to study the shear effects on anchorage interfaces and the transfer of force in slopes under seismic action.Numerous researchers have conducted in-depth studies on the action of force on anchorage interfaces under static action [1,2,3,4,5,6,7], and some have studied the seismic response of anchored slopes by conducting shaking table tests; there are seldom investigations made of the mechanism of anchoring rock and soil mass under dynamic action, which has restricted the application of anchoring technologies of rock and soil mass and the progress of relevant research thereinto [8,9,10,11]
The strain gauge (F, around the upper anchor bolt) on the grout-rock interface of the upper anchor bolt in the weak layer took the lead in recording strain when acceleration amplitudes of Wolong waves input in X-unidirection and X and Z bidirection were increased to 0.4 g and those in the Z-unidirection augmented to 0.5 g, while at the same time, no response was monitored at strain gauges on the bolt-grout interface
Acceleration Response. e seismic response of a slope is closely related to working mechanism of an anchor system, and analysing the seismic response of the slope thereby is helpful for ascertaining the shear effects on the anchorage interfaces. erefore, the most representative seismic response, acceleration response of the slope surface, was selected for analysis

Summary

Introduction

As a common method for supporting rock and soil masses, is extensively used in projects and plays a critical role in major projects due to its unique advantages such as delicate structures, ease of construction, low cost, and high performance; research into mechanisms used for anchoring slopes under seismic action lags far behind engineering practice, so it is necessary to study the shear effects on anchorage interfaces and the transfer of force in slopes under seismic action.Numerous researchers have conducted in-depth studies on the action of force on anchorage interfaces under static action [1,2,3,4,5,6,7], and some have studied the seismic response of anchored slopes by conducting shaking table tests; there are seldom investigations made of the mechanism of anchoring rock and soil mass under dynamic action, which has restricted the application of anchoring technologies of rock and soil mass and the progress of relevant research thereinto [8,9,10,11]. As a common method for supporting rock and soil masses, is extensively used in projects and plays a critical role in major projects due to its unique advantages such as delicate structures, ease of construction, low cost, and high performance; research into mechanisms used for anchoring slopes under seismic action lags far behind engineering practice, so it is necessary to study the shear effects on anchorage interfaces and the transfer of force in slopes under seismic action. Hong et al [12] studied the seismic response of slopes anchored with soil nails under seismic action. Jian-Bin et al [13] investigated the seismic response of lattice beams in slopes supported with framed anchor bolts. Zhi-Xin et al [15] investigated the dynamic response of a rock slope covered with red clay supported with anchor bolts and the distribution of axial forces on anchor bolts under seismic action

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