Creep Behavior of Asphalt Concrete Core Materials in Embankment Dams under a Stepped Loading Path

Abstract: The stress and deformation of rock-fill dam with asphalt concrete core wall founded on deep overburden is calculated and analyzed by Duncan E-ν model and double-yield-surface model through three-dimensional finite element method. The stress and deformation of dams in water storage period is compared by the two models, the results show that the deformation distribution of dam core via two different models are coincide one another. The horizontal displacement and vertical displacement of rock-fill dam with asphalt concrete core wall by double-yield-surface model is smaller than which by Duncan E-ν model in the period of water storage. Furthermore, the horizontal displacement and vertical displacement by double-yield-surface model, which are close to the practical test data through the deformation via two models are in good agreement. The analysis of core-wall stress via double-yield-surface model is more reasonable than the Duncan E-ν model. The analysis result of resisting hydraulic fracturing of core dams by DuncanE-ν model is coincide which of core dams by double-yield-surface model.

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Three-Dimensional Static and Dynamic Analyses of an Asphalt-Concrete Core Dam

Proceedings of GeoShanghai 2018 International Conference: Fundamentals of Soil Behaviours ◽

10.1007/978-981-13-0125-4_65 ◽

2018 ◽

pp. 583-593

Author(s):

Yingli Wu ◽

Xinwen Jiang ◽

Hua Fu ◽

Kai Xu ◽

Zhiqiang Wu

Keyword(s):

Asphalt Concrete ◽

Three Dimensional ◽

Concrete Core ◽

Dynamic Analyses

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Shear modulus reduction and damping ratio curves for earth core materials of dams

Canadian Geotechnical Journal ◽

10.1139/cgj-2017-0529 ◽

2019 ◽

Vol 56 (1) ◽

pp. 14-22 ◽

Cited By ~ 3

Author(s):

DongSoon Park ◽

Tadahiro Kishida

Keyword(s):

Shear Modulus ◽

Dynamic Properties ◽

Damping Ratio ◽

Empirical Relationship ◽

Embankment Dams ◽

In Situ Data ◽

Earth Core ◽

Dynamic Analyses ◽

Modulus Reduction ◽

Core Materials

It is essential to obtain shear modulus reduction and damping ratio curves to perform dynamic analyses of earth-cored embankment dams. Many studies have been performed for dynamic properties of clayey soils, but they have been limited for earth core materials of dams. This study conducted resonant column tests to obtain shear modulus reduction (G/Gmax) and damping ratio (D) curves for 31 specimens (17 undisturbed and 14 remolded specimens) from 13 earth-cored embankment dams. Empirical G/Gmax and D curves are proposed for dynamic properties of clayey earth core materials. Fitting curves are provided by using the functional forms of the Ramberg–Osgood and Darendeli models. The observation shows that the undisturbed earth cores yield relatively higher G/Gmax and lower D curves than the remolded cores. G/Gmax curves of compacted earth cores are relatively higher than those of Vucetic and Dobry curves for a similar level of plasticity index. Uncertainty and bias are calculated by performing residual analysis, which shows that there is no clear bias in predicting G/Gmax and the uncertainties between undisturbed earth core materials and natural deposits are at a similar level. A proposed empirical relationship of G/Gmax and D curves for earth core materials can be utilized for dynamic analyses of embankment dams for cases where there is insufficient in situ data.

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Experimental Study on Hydraulic Fracturing of High Asphalt Concrete Core Rock-Fill Dam

Applied Sciences ◽

10.3390/app9112285 ◽

2019 ◽

Vol 9 (11) ◽

pp. 2285 ◽

Cited By ~ 2

Author(s):

Zhengxing Wang ◽

Jutao Hao ◽

Jian Yang ◽

Yan Cao ◽

Xiulin Li ◽

...

Keyword(s):

Hydraulic Fracturing ◽

Hydraulic Fracture ◽

Asphalt Concrete ◽

Water Pressure ◽

Concrete Core ◽

Mix Proportion ◽

Local Shear ◽

Test Result ◽

Rule Out ◽

Shear Dilatancy

In this paper, we experiment on the hydraulic fracturing of asphalt concrete with a voids content higher than 3%, which has arisen from the possible local shear dilatancy of Quxue asphalt’s core wall of concrete core dam, the highest one of the sort constructed in the world. The model test has shown that under the sole water pressure 0.13 MPa—relevant to the pressure where the dilatancy could appear at core wall of Quxue dam—the asphalt concrete with a voids content of 3.5% underwent hydraulic fracturing. Furthermore, the asphalt concrete with a voids content of 3.0% was tested for nearly 500 h and no sign of hydraulic fracturing was found, which again confirmed the threshold requirement for a 3% voids content to the impervious asphalt concrete to the hydraulic fracture concern. According to the analysis of the test result, the theory of fracture mechanics could be applied to the hydraulic fracture of asphalt concrete with a voids content between 3.4~4.0%, which behaved during hydraulic fracturing like a quasi-brittle material, similar to concrete. Because the hydraulic fracturing could occur in the shear dilatant asphalt concrete, a proper mix proportion of asphalt concrete to a project with adverse stress state should be carefully designed to rule out the possibility of shear dilatancy.

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