Biaxial Failure Criteria Of HSSFCNRC And Their Application In Kilometer Shaft

With the rapid development of social economy, science and technology level and the concrete use of increasingly severe environment, the high strength high performance concrete has become the current and future quite a long period of time a major building materials science and technology development direction. Therefore, this essay carried out relevant research of high strength steel fiber concrete project supported by carbon nanotubes. According to the steel fiber high strength, good toughness, advantages and carbon nanotubes with high strength, low density, toughness. Firstly, it is determined the optimum strength grade of C70-C100 plain concrete and steel fiber reinforced high strength concrete mix ratio of carbon nanotubes;Then the strength, durability, shrinkage and creep, uniaxial compression and biaxial compression were tested; It is show that steel fiber reinforced high strength carbon nanotubes concrete has high strength, good durability, toughness, ductility and other excellent characteristics.The main research contents are as follows:(1) By exploring the test, first of all, determine the scope of high-strength concrete mix, and on this basis the orthogonal experiment, finally got the high-strength concrete(High Strength Plain Concrete, referred to as HSPC) optimal mix; then through a single doped mixed steel fiber and carbon nanotubes, finally got the high-strength steel fiber concrete nanotubes(High Strength Steel Fiber and Carbon Nanotubes Reinforced Concrete, referred to as HSSFCNRC) optimal mix;(2) The HSPC mineral admixture with non-conventional high-strength concrete(High-Strength Concrete without Mineral Admixtures, referred to as HSCwMA),HSPC and HSSFCNRC were comparative analysis in mechanical properties, durability and. The results show that, HSSFCNRC with high strength and good durability;(3) HSPC contraction studied under laboratory conditions creep characteristics of the environment, compared the relative error CEB-FIP(1990) model, B3 model,GL2000 models theoretical and experimental values, test confirmed B3 model predictions and experimental values of the most close to the paper and water- cement ratio, mineral admixtures, humidity, temperature and other aspects of the comprehensive correction, B3 model predictions more accurate amended;(4) For HSPC, HSSFCNRC were carried out uniaxial compressive test, and the establishment of appropriate constitutive relations;(5) HSPC, HSSFCNRC were carried out biaxial compressive test, and establish the biaxial compression failure criterion and constitutive relation;(6) According relation of a mine in Pingdingshan return air shaft relevant information, and concrete biaxial failure criterion and constitutive established in this paper, it is established of a well bore plane strain model and simulation using ANSYS software to simulate the weight of the wall in its confining rock pressure, damage in the form of pore water pressure under the combined effect of the simulation analysis.