钢纤维混凝土的增强机理与断裂力学模型研究

钢纤维因其能为基体裂纹提供桥联而经常被用于增强水泥基材料。为了更好地了解钢纤维混凝土这类复合材料的断裂行为，重点讨论了钢纤维混凝土的增强机理以及裂纹尖端微裂区的力学行为。在一系列理论分析与实验观察的基础上，提出了一个新的钢纤维混凝土材料断裂力学模型，给出了一些有工程实用价值的结论。     

含充填物的厚壁圆筒砂岩的力学性质研究

基于单轴和常规三轴压缩试验,采用完整试样、空心及铝棒充填的厚壁圆筒试样,模拟研究支护对圆形巷道的强度、变形和破坏特征的影响。结果表明:充填试样和完整试样的单轴压缩强度和弹性模量大致相同,而厚壁圆筒试样的强度和弹性模量则偏低31.8%和22.4%;厚壁圆筒试样三轴压缩时出现沿圆周层状破坏,其剪切面积随着围压的增大而减少,围压40 MPa时出现明显塌孔;充填试样进入塑性屈服阶段后,充填物才会对试样的力学性质产生明显影响;充填物改变了孔道内部应力状态,使孔道内壁由原来的二维应力状态恢复到三维应力状态,抑制了孔道内壁的侧向变形,防止自由面岩石的脱落;岩石破坏并不代表承载能力消失,充填试样岩石破坏后失去黏结力,载荷主要通过充填物与岩石、岩石裂隙之间摩擦力共同承载。     

深井开采灾害应对决策技术综述

随着我国浅表有色金属矿床即将消耗殆尽,深井开采在我国今后的矿山开采所占比例将逐步加大,其岩石力学和深井灾害的研究对深井矿山的建设具有重要意义.介绍深井开采的岩石力学问题及深井灾害的特点、灾害控制新思路、决策技术.     

定向钻孔注浆封堵井下突水

详细介绍了高阳铁矿实施大位移定向钻孔注浆方法和工艺参数,其成功的经验对治理矿山井下突水淹井事故具有一定的参考价值.     

高岭土插层改性方法及其复合物的应用

本文分析了高岭土插层改性的机理,综述了高岭土有机插层改性的传统方法及近几年出现的几种新方法,特别是微波辅助插层改性、超声化学法等。此外还介绍了高岭土有机插层纳米复合物在陶瓷材料、光电学功能材料、环保材料、结构材料等方面的应用及前景展望。     

Stability classification model of mine-lane surrounding rock based on distance discriminant analysis method

Based on the principle of Mahalanobis distance discriminant analysis （DDA） theory, a stability classification model for mine-lane surrounding rock was established, including six indexes of discriminant factors that reflect the engineering quality of surrounding rock： lane depth below surface, span of lane, ratio of directly top layer thickness to coal thickness, uniaxial comprehensive strength of surrounding rock, development degree coefficient of surrounding rock joint and range of broken surrounding rock zone. A DDA model was obtained through training 15 practical measuring samples. The re-substitution method was introduced to verify the stability of DDA model and the ratio of mis-discrimination is zero. The DDA model was used to discriminate 3 new samples and the results are identical with actual rock kind. Compared with the artificial neural network method and support vector mechanic method, the results show that this model has high prediction accuracy and can be used in practical engineering.     

Settlement behavior of coal mine waste in different surrounding rock conditions

In order to investigate the influence of complex conditions of in-situ surrounding rocks on the settlement behavior of nubbly coal mine waste subjected to high gravity pressure,four kinds of loading chambers made of different similar materials with different elastic moduli in experiments were used to simulate the deformation features of in-site rocks,including soft,moderate hardness,hard and extra-hard rocks. The results show that all the settlement-axial load （or axial strain-stress） curves obtained under four different surrounding rock conditions present power-exponential function feature. The final settlement of coal mine waste under the same axial load is closely related to the lumpiness gradations and the deformation behavior of chamber materials used to simulate behaviors of different in-situ surrounding rocks. In the same surrounding rock condition,the final settlement under the same maximum axial load decreases with the decrease of the proportion of larger gradation of coal mine waste. While for the same lumpiness gradation case,the settlement increases with the decrease of elastic modulus of simulated surrounding rocks and the lateral pressure induced by axial load increases with the increase of elastic modulus of loading chambers that are used to simulate different surrounding rocks. The test results also reveal that both the compaction curve and lateral pressure curve show a three-stage behavior,and the duration of each stage,which is closely related to gradations and the deformation feature of loading chamber materials,decreases with the increase of the proportion of the small size of coal mine waste and elastic modulus of the simulated rock materials.     

Strength evolution law of cracked rock based on localized progressive damage model

In the light of the localized progressive damage model, the evolution law of cohesive and frictional strength with irreversible strains was determined. Then, the location and the extent of the excavation disturbed zone in one deep rock engineering were predicted by using the strength evolution law. The theoretical result is close to the result of in-situ test. The strength evolution law excels the elastic-perfectly plastic model and elasto-brittte plastic model in which the cohesive and frictional strength are mobilized simultaneously. The results obtained indicate that the essential failure mechanism of the cracked rock can be described by the cohesion weakening and friction strengthening evolution law.     

Features of energy distribution for blast vibration signals based on wavelet packet decomposition

Blast vibration analysis constitutes the foundation for studying the control of blasting vibration damage and provides the precondition of controlling blasting vibration. Based on the characteristics of short-time nonstationary random signal, the laws of energy distribution are investigated for blasting vibration signals in different blasting conditions by means of the wavelet packet analysis technique. The characteristics of wavelet transform and wavelet packet analysis are introduced. Then, blasting vibration signals of different blasting conditions are analysed by the wavelet packet analysis technique using MATLAB; energy distribution for different frequency bands is obtained. It is concluded that the energy distribution of blasting vibration signals varies with maximum decking charge,millisecond delay time and distances between explosion and the measuring point. The results show that the wavelet packet analysis method is an effective means for studying blasting seismic effect in its entirety, especially for constituting velocity-frequency criteria.