作者机构：
[Jiang, Xueliang; Yang, Hui] Guangdong Provincial Key Laboratory of Green Construction and Intelligent Operation & Maintenance for Offshore Infrastructure, Guangzhou Maritime University, Guangzhou, 510725, China;[Wang, Haodong; Wei, Zhenzhen; Jiang, Xueliang; Shen, Bo; Yang, Hui] school of civil engineering, Central South University of Forestry and Technology, Changsha, 410004, China;[Yin, Jun] school of civil engineering, Central South University of Forestry and Technology, Changsha, 410004, China. yinjun0509@163.com
通讯机构：
[Yin, Jun] s;school of civil engineering, Central South University of Forestry and Technology, Changsha, 410004, China.
关键词：
HHT transform;Living stumps slope;Marginal spectrum;Seismic dynamic response;Shaking table test
摘要：
A large-scale shaking table test of a living stump slope with a geometric similarity ratio of 1:7 was designed and completed. The peak acceleration, acceleration amplification factor, and displacement response patterns of living stumps slopes under different types of seismic waves and excitation intensities were obtained. The time-frequency and energy variation characteristics were analyzed using the Hilbert-Huang Transform (HHT). The results showed that: (1) Regardless of the type of seismic wave, the peak acceleration and acceleration amplification factor of the living stumps slope surface are positively correlated with relative height and seismic excitation intensity. When the excitation intensity is ≤ 0.4g, the acceleration amplification effect is more pronounced; when the excitation intensity is > 0.4g, the acceleration amplification effect weakens. (2) Under the action of different seismic waves, the peak displacement of slope surface shows amplification effect along the elevation, and increases with the increase of excitation intensity. In addition, the incremental displacement gradually decreases from the toe to the top of the slope, which is expressed as D2 > D3 > D1 > D4 > D5. The peak displacement at the top of the slope is the greatest, but the incremental displacement is the smallest; the peak displacement at the toe of the slope is the smallest, but the incremental displacement is relatively large. (3) Regardless of the type of seismic wave, living stumps slope shows the characteristics of filtering the low-frequency components of the seismic waves and amplifying their high-frequency components. At the same time, the seismic Hilbert energy gradually accumulates along the elevation. PSHEA and PMSA significantly increase with elevation and excitation intensity, and they reach the maximum at the top of the slope. (4) The seismic Hilbert energy is positively correlated with the relative height and excitation intensity, and reaches the maximum at the top of the slope. With the accumulation of seismic Hilbert energy increases, the dynamic response parameters such as peak acceleration, acceleration amplification coefficient and displacement also increase synchronously, reaching the maximum at the top of the slope. The research conclusions can provide an experimental basis for the seismic design of living stumps slopes.
摘要：
In order to investigate the dynamic response of embankment slopes supported by wooden frame beams and bamboo anchor rods under train loading, this study conducted model tests on embankment slopes supported by wooden frame beams and bamboo anchor rods and carried out three-dimensional numerical simulations of the slopes. This study focused on analyzing the effects of train loading frequency, the peak value difference, and the peak value of the soil pressure on the embankment slopes. This study also analyzed the horizontal displacement of the slope surface, the internal forces in the support structure, and the slope safety factor. The results indicated the following: (1) The increase in loading frequency from 2 Hz to 3 Hz resulted in a significant increase in dynamic soil pressure, with a smaller increase observed upon further frequency increments. Moreover, increasing the load or peak value difference led to an overall increase in the maximum dynamic soil pressure. (2) Under various loading conditions, the axial force in the top anchor rod was significantly greater than that in the middle anchor rod. Additionally, the axial force in the rod body exhibited a pattern of larger forces near the anchorage end and smaller forces near the anchor head. The location of the maximum bending moment in the anchor rod transitioned from the anchor head to the anchorage end as the slope depth increased. The bending moment of the anchor rod increased with the loading frequency but decreased with an increase in the peak value, showing a minor influence from the upper and lower peak values. (3) With the presence of this support system, the slope safety factor increased by 20.13%. A noticeable reduction in the horizontal displacement of the slope surface was observed, with the greatest reduction in the top slope area, followed by the slope angle.
通讯机构：
[Liu, WJ; Wang, HD ] C;Cent South Univ Forestry & Technol, Sch Civil Engn, Changsha 410018, Peoples R China.
关键词：
living stump;slope model test;three-dimensional root;mechanical characteristics;slope reinforcement mechanism
摘要：
As a novel technology for slope protection, living stumps have demonstrated the ability to significantly enhance slope stability. This study aims to investigate the mechanical properties of living-stump root systems and their reinforcement mechanisms on slopes through three-dimensional modeling tests. Using ABS materials, a 3D model of a living elm stump was created via 3D printing; this was followed by slope model testing. The reinforcement mechanisms of living stumps were examined through a combination of model testing and numerical simulation. The results reveal that the presence of living stumps in the lower and middle sections of a slope causes the maximum-shear-stress zone of the soil to shift deeper. The stress distribution around the living stump is notably improved owing to the lateral root system. Living stumps positioned in the lower part of the slope intersect the potential sliding surface, gradually transferring soil shear stress to the root system through root-soil interactions. Furthermore, the tap roots and lateral roots of living stumps form a robust spatial network that can collectively withstand soil shear stress, thereby enhancing slope stability.
期刊：
International Journal of Geosynthetics and Ground Engineering,2024年10(3):1-12 ISSN：2199-9260
通讯作者：
Jiayu Chen
作者机构：
School of Civil Engineering, Guangzhou Maritime University, Guangzhou, China;[Jiayu Chen; Penghui Li; Jiahui Guo] School of Civil Engineering, Central South University of Forestry and Technology, Chang Sha, China;[Xueliang Jiang; Hui Yang] School of Civil Engineering, Guangzhou Maritime University, Guangzhou, China<&wdkj&>School of Civil Engineering, Central South University of Forestry and Technology, Chang Sha, China
通讯机构：
[Jiayu Chen] S;School of Civil Engineering, Central South University of Forestry and Technology, Chang Sha, China
关键词：
Red clay soil reinforced with rice straw;Hysteretic curves;Dynamic property;Dynamic triaxial test
摘要：
The dynamic triaxial test is conducted on the straw-reinforced red clay under different conditions (straw reinforcement rate, confining pressure, and frequency) using British GDS dynamic triaxial apparatus. Five parameters, which are slope k of the long axis of the hysteretic curve, the ratio α of the long axis to the short axis of the hysteretic curve, the distance d between the two centers of the adjacent hysteretic curve, the area S of hysteretic curve, and the residual strain εp, are used to quantitatively study the morphological characteristics of hysteretic curves. The results show that S, d, α, and εp of the hysteretic curve of straw-reinforced red clay increase prominently with the increase of dynamic load, and decrease with increasing confining pressure and frequency. k decreases logarithmically with the increase of dynamic load, and increases with rising frequency and confining pressure. Under the same dynamic stress amplitude and five different reinforcement conditions, the specimen is characterized by the highest dynamic strength, optimal deformation resistance, and excellent reinforcement performance when the reinforcement rate is 0.2%. Compared with the red clay unreinforced with straw, the straw-reinforced red clay has an increased stiffness and elastic modulus, and decreased viscosity, energy dissipation capacity, microscopic damage, and residual plastic strain of soil. To sum up, the dynamic properties of straw-reinforced red clay are significantly improved compared with that of red clay unreinforced with straw.
期刊：
Bulletin of Engineering Geology and the Environment,2023年82(12):1-16 ISSN：1435-9529
通讯作者：
Wenchen Fan
作者机构：
[Wenchen Fan; Hui Yang] School of Civil Engineering, Central South University of Forestry and Technology, Changsha, China;[Guodong Tang] China Railway Siyuan Survey and Design Group Co., Ltd., Wuhan, China;[Dongya Han] School of Resources and Safety Engineering, Central South University, Changsha, China
通讯机构：
[Wenchen Fan] S;School of Civil Engineering, Central South University of Forestry and Technology, Changsha, China
摘要：
Fractures are commonly found throughout rock masses. The propagation and coalescence of these fractures can significantly weaken the surrounding rock strength during underground excavations. In order to investigate the cracking behavior of pre-existing fractures affected by excavation unloading, this study proposed an innovative laboratory excavation test to simulate excavation unloading in deep rock masses. Corresponding numerical stepped excavation tests were also conducted using RFPA (Realistic Failure Process Analysis). The excavation area in specimen was pre-filled with polylactic acid (PLA), and stepped excavation under constant normal stress was performed using an electric cutter. The results reveal that the stress-strain curves of the specimens during stepped excavation can be categorized into four stages based on deformation behavior and the crack process. There are four different patterns of crack coalescence, ultimately leading to specimen failure. Numerical results indicate that the inhomogeneous deformation caused by stepped excavation is responsible for crack initiation, propagation, and eventual specimen failure. The rock bridges between fissures and excavation areas break in three modes: shear sliding, segregation due to tensile cracks, and the formation of ubiquitous fractures. Furthermore, the inclination of the fissure and the initial normal load applied to the specimens have a significant impact on the crack coalescence modes and initiation. These findings can contribute to a better understanding of crack evolution behaviors, including initiation, propagation, coalescence, and transfixion, during excavation unloading in underground engineering projects.
作者机构：
[Fan, Wenchen; Jiang, Xueliang; Yang, Hui] Cent South Univ Forestry & Technol, Sch Civil Engn, Changsha 410004, Hunan, Peoples R China.;[Fan, Wenchen] Changsha Univ Sci & Technol, Engn Res Ctr Catastroph Prophylaxis & Treatment R, Minist Educ, Changsha 410114, Hunan, Peoples R China.;[Cao, Ping] Cent South Univ, Sch Resources & Safety Engn, Changsha 410083, Hunan, Peoples R China.
通讯机构：
[Wenchen Fan] S;School of Civil Engineering, Central South University of Forestry and Technology, Changsha, Hunan 410004, China<&wdkj&>Engineering Research Center of Catastrophic Prophylaxis and Treatment of Road & Traffic Safety of Ministry of Education, Changsha University of Science & Technology, Changsha, Hunan 410114, China
期刊：
Geotechnical and Geological Engineering,2020年38(2):1409-1430 ISSN：0960-3182
通讯作者：
Jiang, Xueliang(15675101471@163.com)
作者机构：
[Niu, Jiayong; Jiang, Xueliang; Yang, Hui] School of Civil Engineering, Central South University of Forestry and Technology, Changsha;410004, China;Department of Geotechnical Engineering, School of Civil Engineering, Southwest Jiaotong University, Chengdu;610031, China;[Wang, Feifei] Changsha Institute of Mining Research Co., Ltd, Changsha
通讯机构：
[Xueliang Jiang] S;School of Civil Engineering, Central South University of Forestry and Technology, Changsha, China
关键词：
Dynamic response;Earthquake;Numerical analysis;Rock tunnel slope;Shaking table test
期刊：
Advances in Civil Engineering,2018年2018:1-10 ISSN：1687-8086
通讯作者：
Yang Hui
作者机构：
[Yang Hui; Lian Pengyuan; Jiang Xueliang] Cent South Univ Forestry & Technol, Coll Civil Engn, Changsha 410018, Hunan, Peoples R China.;[Yang Hui; Jiang Xueliang] Cent South Univ Forestry & Technol, Rock & Soil Engn Res Inst, Changsha 410018, Hunan, Peoples R China.
通讯机构：
[Yang Hui] C;Cent South Univ Forestry & Technol, Coll Civil Engn, Changsha 410018, Hunan, Peoples R China.;Cent South Univ Forestry & Technol, Rock & Soil Engn Res Inst, Changsha 410018, Hunan, Peoples R China.
摘要：
<jats:p>In order to study the internal force characteristics of shallow-bias tunnel with a small clear distance in earthquake, a large-scale shaking table slope model test was designed, and the geometric scale was 1 : 10. In the model test, the Wenchuan (WC) seismic wave was used as the excitation wave. Then, the three-dimensional numerical model was established by using MIDAS-NX, and the reliability of the numerical model was verified by comparing the acceleration of the test results. The axial force, bending moment, and shear force of the tunnel cross section and longitudinal direction were calculated by the numerical model under different excitation directions included the horizontal direction (<jats:italic>X</jats:italic>), the vertical direction (<jats:italic>Z</jats:italic>), and the horizontal and vertical direction (<jats:italic>XZ</jats:italic>). The results show the following. (1) The internal force of right arch foot of left hole and the left arch foot of right hole is larger than other part of the tunnels because the distance between the two tunnels is smaller and they interact with each other. (2) The loading direction of single direction loading method is different and the variation trend of tunnel force are different, so the loading direction of seismic wave has a significant influence on the seismic force response of the tunnel. (3) All of the internal force values of tunnel lining under the seismic wave action in bidirection are larger than those in single direction. The value is not a simple superposition of two directions and has some coupling effect. The influence of the vertical seismic wave cannot be ignored in dynamic response research. These results improve the understanding of the rock slope with small spacing tunnel under seismic action.</jats:p>
