Study on Creep Characteristics and Constitutive Relation of Fractured Rock Mass
In order to effectively describe the whole creep process of fractured rock mass, triaxial unloading creep tests were carried out on prefractured coal samples using constant axial pressure and graded unloading confining pressure, and the axial and lateral creep laws of fractured coal samples with dif...
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| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Wiley
2020-01-01
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| Series: | Shock and Vibration |
| Online Access: | http://dx.doi.org/10.1155/2020/8833512 |
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| author | Maotong Li Kesheng Li Deng Zhang Chuanxiao Liu Depeng Ma |
| author_facet | Maotong Li Kesheng Li Deng Zhang Chuanxiao Liu Depeng Ma |
| author_sort | Maotong Li |
| collection | DOAJ |
| description | In order to effectively describe the whole creep process of fractured rock mass, triaxial unloading creep tests were carried out on prefractured coal samples using constant axial pressure and graded unloading confining pressure, and the axial and lateral creep laws of fractured coal samples with different dip angles were studied. Combined with the characteristics of creep curve and based on Kachanov’s creep damage theory, the damage variable is introduced into the constitutive relation and creep equation, and the evolution equation of damage variable with time in the whole creep process is derived. At the same time, a new method to calculate the initial damage is proposed. The elastoplastic body with damage variable is connected with the Burgers model in series. Meanwhile, lade criterion and switch element are introduced into the creep model to establish a new fracture damage creep model. The one-dimensional and three-dimensional damage creep equations are derived. The damage creep equation is obtained according to the superposition principle. A simple and feasible method for parameter identification of the model is given based on the characteristics of creep curve. The applicability of the model is verified by comparing the creep test curve of fractured coal sample with the theoretical curve. The results show that the two models are in good agreement. The model can not only accurately reflect the nonlinear characteristics of creep curves in the attenuation and isokinetic stages but also describe the accelerated creep characteristics of fractured rocks. |
| format | Article |
| id | doaj-art-b2a0211b8bce4b9493cdd22d96b3a95a |
| institution | Kabale University |
| issn | 1070-9622 1875-9203 |
| language | English |
| publishDate | 2020-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | Shock and Vibration |
| spelling | doaj-art-b2a0211b8bce4b9493cdd22d96b3a95a2025-02-03T00:59:41ZengWileyShock and Vibration1070-96221875-92032020-01-01202010.1155/2020/88335128833512Study on Creep Characteristics and Constitutive Relation of Fractured Rock MassMaotong Li0Kesheng Li1Deng Zhang2Chuanxiao Liu3Depeng Ma4College of Water Conservancy and Civil Engineering, Shandong Agricultural University, Tai’an 271018, Shandong, ChinaCollege of Water Conservancy and Civil Engineering, Shandong Agricultural University, Tai’an 271018, Shandong, ChinaCollege of Water Conservancy and Civil Engineering, Shandong Agricultural University, Tai’an 271018, Shandong, ChinaCollege of Water Conservancy and Civil Engineering, Shandong Agricultural University, Tai’an 271018, Shandong, ChinaCollege of Water Conservancy and Civil Engineering, Shandong Agricultural University, Tai’an 271018, Shandong, ChinaIn order to effectively describe the whole creep process of fractured rock mass, triaxial unloading creep tests were carried out on prefractured coal samples using constant axial pressure and graded unloading confining pressure, and the axial and lateral creep laws of fractured coal samples with different dip angles were studied. Combined with the characteristics of creep curve and based on Kachanov’s creep damage theory, the damage variable is introduced into the constitutive relation and creep equation, and the evolution equation of damage variable with time in the whole creep process is derived. At the same time, a new method to calculate the initial damage is proposed. The elastoplastic body with damage variable is connected with the Burgers model in series. Meanwhile, lade criterion and switch element are introduced into the creep model to establish a new fracture damage creep model. The one-dimensional and three-dimensional damage creep equations are derived. The damage creep equation is obtained according to the superposition principle. A simple and feasible method for parameter identification of the model is given based on the characteristics of creep curve. The applicability of the model is verified by comparing the creep test curve of fractured coal sample with the theoretical curve. The results show that the two models are in good agreement. The model can not only accurately reflect the nonlinear characteristics of creep curves in the attenuation and isokinetic stages but also describe the accelerated creep characteristics of fractured rocks.http://dx.doi.org/10.1155/2020/8833512 |
| spellingShingle | Maotong Li Kesheng Li Deng Zhang Chuanxiao Liu Depeng Ma Study on Creep Characteristics and Constitutive Relation of Fractured Rock Mass Shock and Vibration |
| title | Study on Creep Characteristics and Constitutive Relation of Fractured Rock Mass |
| title_full | Study on Creep Characteristics and Constitutive Relation of Fractured Rock Mass |
| title_fullStr | Study on Creep Characteristics and Constitutive Relation of Fractured Rock Mass |
| title_full_unstemmed | Study on Creep Characteristics and Constitutive Relation of Fractured Rock Mass |
| title_short | Study on Creep Characteristics and Constitutive Relation of Fractured Rock Mass |
| title_sort | study on creep characteristics and constitutive relation of fractured rock mass |
| url | http://dx.doi.org/10.1155/2020/8833512 |
| work_keys_str_mv | AT maotongli studyoncreepcharacteristicsandconstitutiverelationoffracturedrockmass AT keshengli studyoncreepcharacteristicsandconstitutiverelationoffracturedrockmass AT dengzhang studyoncreepcharacteristicsandconstitutiverelationoffracturedrockmass AT chuanxiaoliu studyoncreepcharacteristicsandconstitutiverelationoffracturedrockmass AT depengma studyoncreepcharacteristicsandconstitutiverelationoffracturedrockmass |