The shear resistance of ballast under dynamic loading directly affects the stability and bearing capacity of the ballast bed; however, the influence of load characteristics on direct shear parameters remains insufficiently understood. A direct shear testing scheme for premium-grade ballast was presented in this study, utilising a dynamic direct shear apparatus configured to accommodate varying characteristics of dynamic loading. Twelve loading conditions were tested, including constant normal load shear and dynamic normal load shear at different frequencies and amplitudes. The effects of these parameters on shear strength, vertical deformation, particle breakage, vertical dynamic stiffness, and damping were analyzed. Results indicate that, under identical static loads, dynamic normal loading exerts little influence on the initial shear force but either strengthens or weakens shear strength. High-frequency loading weakens shear strength, whereas high-amplitude loading strengthens it. Dynamic normal loading suppresses the shear dilation effect, leading the ballast towards a stable compressive state during shearing and causing greater particle breakage. Both compressive deformation and particle breakage increase nonlinearly with the frequency and amplitude of dynamic loading. In addition, ballast dissipates energy through intrinsic damping, achieving a relatively stable dynamic stiffness in the later stages of shearing. These findings provide theoretical support for the scientific maintenance and operation of railway ballast beds.
GuoYMarkineVJingG. Review of ballast track tamping: mechanism, challenges and solutions. Constr Build Mater2021; 300: 123940.
2.
AbbasiAZakeriJANorouziE, et al.Field investigation on the effect of the tamping machine and dynamic track stabilizer on changing the rail support modulus. Proc Inst Mech Eng Part F-J Rail Rapid Transit2024; 238: 1072–1083.
3.
GuQZhaoCBianX, et al.Trackbed settlement and associated ballast degradation due to repeated train moving loads. Soil Dynam Earthq Eng2022; 153: 107109.
4.
ShiCFanZConnollyDP, et al.Railway ballast performance: recent advances in the understanding of geometry, distribution and degradation. Transp Geotech2023; 41: 101042.
5.
ZhangXZhaoCZhaiW, et al.Investigation of track settlement and ballast degradation in the high-speed railway using a full-scale laboratory test. Proc Inst Mech Eng Part F-J Rail Rapid Transit2019; 233: 869–881.
6.
WuA,Sun Y. Granular dynamic theory and its applications. Springer Berlin Heidelberg, 2008.
7.
SuikerASJSeligETFrenkelR. Static and cyclic triaxial testing of ballast and subballast. J Geotech Geoenviron Eng2005; 131: 771–782.
8.
IndraratnaBThakurPKVinodJS. Experimental and numerical study of railway ballast behavior under cyclic loading. Int J GeoMech2010; 10: 136–144.
9.
SunQDIndraratnaBNimbalkarS. Deformation and degradation mechanisms of railway ballast under high frequency cyclic loading. J Geotech Geoenviron Eng2016; 142: 4015056.
10.
BianXJiangJJinW, et al.Cyclic and postcyclic triaxial testing of ballast and subballast. J Mater Civ Eng2016; 28: 04016032.
11.
AlavijehBEMokhtariMAraeiAA. Behavior of fresh and recycled slag ballast under cyclic and post-cyclic monotonic loadings using large-scale triaxial tests. Soil Dynam Earthq Eng2024; 182: 108720.
12.
DangWKonietzkyHFruehwirtT. Direct shear behavior of a plane joint under dynamic normal load (DNL) conditions. Eng Geol2016; 213: 133–141.
13.
GuQZhangQYeS, et al.Experimental and numerical investigations on the shear mechanical behaviors and damage evolution characteristics of 3D rock joint surfaces under dynamic normal load. Rock Mech Rock Eng2025; 58: 6087–6113.
14.
BoettcherMSMaroneC. Effects of normal stress variation on the strength and stability of creeping faults. J Geophys Res-Solid Earth2004; 109: B03406.
15.
DangWChenJHuangL. Experimental study on the velocity-dependent frictional resistance of a rough rock fracture exposed to normal load vibrations. Acta Geotech2021; 16: 2189–2202.
16.
DangWLiuYLiS, et al.Direct shear behavior of dredged soil under dynamic normal load conditions. Soil Dynamics and Earthquake Engineering2023; 168: 107851.
17.
DangWChenJHuangL, et al.Frictional behavior of granular materials exposed to dynamic normal load. Eng Geol2021; 295: 106414.
18.
LiuFYZhuCYuanGH, et al.Behaviour evaluation of a gravelly soil-geogrid interface under normal cyclic loading. Geosynth Int2021; 28: 508–520.
19.
YinXZhouTZhouC, et al.Rate- and normal stress-dependent mechanical behavior of rock under direct shear loading based on a bonded-particle model (BPM). Rock Mech Rock Eng2023; 56: 7959–7979.
20.
IndraratnaBNgocTNRujikiatkamjornC. Behavior of geogrid-reinforced ballast under various levels of fouling. Geotext Geomembr2011; 29: 313–322.
21.
NgocTNIndraratnaBRujikiatkamjornC. Modelling geogrid-reinforced railway ballast using the discrete element method. Transp Geotech2016; 8: 86–102.
22.
OroszAFarkasZTamasK. Experimental investigation of mixing railway ballast grains with different form using large-scale direct shear box apparatus. Transp Geotech2023; 42: 101105.
23.
WangJ-QZhangT-YDongC-F, et al.Quantifying railway ballast degradation through repeated large-scale direct shear tests and three-dimensional morphological analysis. Int J GeoMech2025; 25: 04025017.
24.
SwetaKHussainiSKK. Behavior evaluation of geogrid-reinforced ballast-subballast interface under shear condition. Geotextiles and Geomembranes2019; 47: 23–31.
25.
ChiYXiaoHCuiX, et al.Research on the mechanism of railway ballast shear performance under various sand contents and load conditions. Comput Part Mech2024; 11: 2995–3012.
26.
XiaoJZhangXZhangD, et al.Three-dimensional discrete element simulation of ballast direct shear testing in vibration field. Geotech Geol Eng2021; 39: 157–169.
27.
ChinaTMOR. Railway ballast (TB/T 2140-2008): Railway industry standard of the people’s Republic of China2008.
28.
EsveldC. Modern railway track. Zaltbommel. MRT-productions, 2001.
29.
JeffsTTewGP. A review of track design procedures: sleepers and ballast. Railways of Australia1991; 2.
30.
ZhaoBWangXZhangC, et al.Structural integrity assessment of shield tunnel crossing of a railway bridge using orthogonal experimental design. Eng Fail Anal2020; 114: 104594.
31.
LiuGDaiJWangP, et al.Analysis of the breakage parameters of railway ballast based on the discrete element method. J Zhejiang Univ-SCI A2023; 24: 257–271.
32.
EsmaeiliMPourrashnooA. Experimental investigation of shear strength parameters of ballast encased with geogrid. Constr Build Mater2022; 335: 127491.
33.
IndraratnaBLackenbyJChristieD. Effect of confining pressure on the degradation of ballast under cyclic loading. Geotechnique2005; 55: 325–328.
34.
NavaratnarajahlSKIndraratnaB. Use of rubber mats to improve the deformation and degradation behavior of rail ballast under cyclic loading. J Geotech Geoenviron Eng2017; 143: 04017015.
35.
ASTM. Standard test methods for the determination of the modulus and damping properties of soils using the cyclic triaxial apparatus. ASTM D3999, 2003.
36.
EsmaeiliMAskariA. Laboratory investigation of the cyclic behavior of rock ballast mixed with slag ballast for use in railway tracks. Constr Build Mater2023; 365: 130136.
37.
TanPXiaoYWangM, et al.Insights into particle breakage induced macroscopic and microscopic behavior of railway ballast via DEM. Comput Geotech2025; 182: 107135.
38.
TanPXiaoYWangM, et al.Insights into particle breakage induced macroscopic and microscopic behavior of ballast materials under repeated load triaxial compression via DEM. Constr Build Mater2025; 473: 140857.
39.
ZhangRZhangLShiC, et al.Microscopic mechanical properties of rockfill materials under different stress paths. Granul Matter2024; 26: 41.
40.
SadeghiJToloukianAZareiMA, et al.Improvement of ballast behavior by inclusion of tire-derived aggregates with optimum size. Constr Build Mater2025; 458: 139530.
41.
PrasadKVSHussainiSKK. Behavior evaluation of geogrid-polyurethane composite-stabilized ballast. J Mater Civ Eng2024; 36: 04024173.
42.
IndraratnaBVinodJSLackenbyJ. Influence of particle breakage on the resilient modulus of railway ballast. Geotechnique2009; 59: 643–646.
