A New Dilation Angle Model for Rocks

Zhao, Rong; Li, Chunguang

doi:10.1007/s00603-022-02835-6

Cited by 6 publications

(1 citation statement)

References 34 publications

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“…Molladavoodi and Rahmati [25] studied the influence of dilation angle variation on the deformation of the plastic zone around tunnels through analytical and numerical methods. In the studies conducted by Zhang et al [26] and Wang et al [27], the dilatancy angle gets larger under higher confining pressure, but Zhao and Li [28] and Chen et al [29] observed the opposite relationships where the dilatancy angle decreased as the confining pressure rose. Among the research on the plastic deformation dependency of dilatancy angle, the plastic shear strain was found to be a suitable internal parameter to quantitatively characterize the evolution of the dilatancy angle [20].…”

Section: Introductionmentioning

confidence: 96%

Experimental Study on the Dilatancy and Energy Evolution Behaviors of Red-Bed Rocks under Unloading Conditions

Zheng,

Liu,

Zhuo

et al. 2023

Materials

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Surrounding rock deformation and consequent support failure are the most prominent issues in red-bed rock tunnel engineering and are mainly caused by the effects of unloading, rheology, and swelling. This study investigated the mechanical responses of two kinds of red-bed mudstone and sandstone under unloading conditions via laboratory observation. Volume dilation was observed on the rocks during unloading, and the dilatancy stress was linear with the initial confining pressure. However, the ratios of dilatancy stress to peak stress of the two rocks kept at a range from 0.8 to 0.9, regardless of confining pressures. Both the elastic strain energy and the dissipated energy evolved synchronously with the stress–strain curve and exhibited conspicuous confining pressure dependence. Special attention was paid to the evolution behavior of the dilatancy angle. The dilatancy angle changed linearly during unloading. When the confining pressure was 10 MPa, the dilatancy angle of mudstone decreased from 26.8° to 12.5° whereas the dilatancy angle of sandstone increased from 34.6° to 51.1°; when the confining pressure rose to 25 MPa, the dilatancy angle of mudstone and sandstone decreased from 45.8° to 17.4° and increased from 21.7° to 39.5°, respectively. To further understand the evolution of the dilatancy angle, we discussed the links between the variable dilatancy angle and the processes of rock deformation and energy dissipation.

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