Evaluation of Mode Ⅰ Fracture Toughness of Rock Based on Brittleness Index of Strength Parameters(PDF)
《建筑科学与工程学报》[ISSN:1673-2049/CN:61-1442/TU]
- Issue:
- 2018年04期
- Page:
- 97-104
- Research Field:
- Publishing date:
Info
- Title:
- Evaluation of Mode Ⅰ Fracture Toughness of Rock Based on Brittleness Index of Strength Parameters
- Author(s):
- BAO Han; GUO Wen-ming; ZHANG Guo-biao; YAN Chang-gen
- School of Highway, Chang’an University
- Keywords:
- mode Ⅰ fracture toughness; brittleness index; strength parameter; multi strength index; optimization model
- PACS:
- -
- DOI:
- -
- Abstract:
- On the basis of experimental data collection, three typical strength brittleness indices were selected as the investigation object. The linear relationship between mode Ⅰ fracture toughness and brittleness index was established, and the mode Ⅰ fracture toughness parameterization models of rock based on different brittleness indices was obtained. The cross validation method was adopted to get the accurate model parameters, and the simulation results were tested to evaluate the applicability and differences between the models. The results show that the three evaluation models have strong reliability in evaluating and predicting the mode Ⅰ fracture toughness of rock, and can be used to evaluate the mode Ⅰ fracture toughness of rock by means of brittleness index. There are certain differences in the evaluation and prediction accuracy of the three models. On the whole, the evaluation model based on the Mohr circle brittleness index is superior to the compressiontension strength brittleness index evaluation model and the compression strength brittleness index evaluation model. It is proved that the mode Ⅰ fracture toughness is the embodiment of the comprehensive mechanical properties of rock, and a more accurate and reasonable mode Ⅰ fracture toughness value will be obtained by using the multi strength index to establish the evaluation model. Because of the convenience of the compressive strength, the evaluation model built with it also has high evaluation accuracy. In the requirement of rapid evaluation, the mode Ⅰ fracture toughness evaluation model of rock based on the compression brittleness index can be considered.
Last Update: 2018-07-18