岩石力学室内试验装置的新进展—RMT—64岩石力学试验系统

采用先进的设计方案、独特的结构布局，并采用了计算机直接控制和自适应控制技术，研制了一套功能多样化、体积小型化的ＲＭＴ—６４岩石力学试验系统，并进行了初步试验研究。该系统进行单轴压缩试验时对脆性明显的岩类大都能在纵向变形率控制下获得全过程曲线，而使用进口的电液伺服机时往往难以做到。这些试验结果已经为研究岩石力学的某些重大理论问题提供了依据。由于７０年代初由国际著名学者提出的并沿用至今的关于岩石Ⅰ型、Ⅱ型分类准则与这些最新的试验成果不相符合，作者认为Ⅰ型、Ⅱ型分类概念应重新考虑     

岩石力学试验及工程应用

岩石力学试验研究应做到理论与实际的统一,并应用于工程的效果。本文在国内外成果研究的基础上,根据我所历年来的试验资料和笔者近年来工作经验,对岩石力学试验与地质体特点进行探讨。文中阐述岩石抗压强度(Cc)破坏机理与基础允许承载力[R]的经验力学模式,岩体抗剪断(f)与(c)值的比配关系图式,以及不同类别岩体弹性模量(E)与弱结构面内夹的物质厚度(h)的关系曲线。     

福怡大厦岩石力学试验数据的分析和应用

结合广州市福怡大厦施工阶段工程地质勘察中岩石极限抗压强度试验指标的分析和运用，说明了对试验数据分析的重要性及应注意的问题。     

用于填筑狭小地下空间的流态水泥土材料室内试验研究

用人工拌制的流态水泥土材料填筑狭小的地下空间可以有效解决回填土质量控制难题。对拌制的流态水泥土进行了室内无侧限抗压强度试验和直剪试验,研究了不同水泥掺量、水灰质量比、养护方式、养护时间对水泥土强度的影响,并获取了水泥土材料的变形模量、黏聚力和内摩擦角。用南京典型粉质黏土拌制的水泥土变形模量98.4~112.7 MPa、黏聚力185.54~213.45 kPa、内摩擦角32°~39°,可以有效降低回填区周边的不均匀沉降。     

（单点法）求岩石抗剪强度指标φ、C值试验成功

岩土体的φ、C值指标的确定主要是靠取样室内试验和现场原位试验。目前国内外工程地质勘测及岩体力学试验中多用<多点法>,即用三块以上岩样求出τ-δt_gφ c关系曲线。其特点是现场原位试验,因制备试件往往非常困难,特别对一些软弱岩体就更困难;而且要打试验平硐,试验费昂贵。为解决这一课题,江西工业大学土建系张景德、宋寿南等人,经过     

不同试验方式岩石点荷载强度与单轴抗压强度对比分析

对重庆地区常见的砂岩、泥岩和灰岩进行了轴向、径向和不规则体三种试样的点荷载试验及单轴抗压强度试验,将试验所得点荷载强度值和单轴抗压强度值进行对比分析。结果表明:利用点荷载试验可以比较好地获得该地区的砂岩、泥岩和灰岩的单轴抗压强度值。相比于不规则试件,用规则试件进行点荷载试验得到的结果更加准确、可靠,且通过轴向和径向试验获得的强度值基本一致。     

海底管线地区粘土不排水抗剪强度参数的室内试验研究

本文通过海洋粘土样的几组ＣＩＵ三轴压缩试验发现：此种粘土的ＳＵ具有归一化行为，其Ｓｕ／σＶＣ－ＯＣＲ关系曲线同世界上其他地区的几种粘土具有可比性，尤其与另外两种海洋粘土十分接近。     

黄土坡滑坡滑带土非饱和力学特性试验研究

以三峡库区黄土坡滑坡临江I号崩滑体的滑带土为研究对象,研究基质吸力对非饱和滑带土的强度与变形等力学性质的影响。利用GDS非饱和反压直剪仪对滑带土进行了不同净法向应力和基质吸力组合下的直剪试验。试验结果表明:相同的基质吸力作用下,滑带土抗剪强度随着净法向应力的增大而增大。当滑带土试样中基质吸力较小时(50kPa),试样剪切过程中的应力-应变曲线,随着净法向应力的增大表现为应变硬化型。之后随着基质吸力的增加,当吸力大于净法向应力时,剪切应力-应变曲线表现为较明显的达到峰值后软化。反之,应力-应变曲线表现为应变硬化型。相同净法向应力下,抗剪强度随着吸力的增大而增大,剪切应力-应变曲线由低法向应力下的达到峰值后软化向高法向应力下的应变硬化转变。剪切过程的轴向位移表现为:当吸力大于净法向应力时,表现为剪胀; 反之,表现为剪缩。滑带土固结排水剪切条件下得到的黏聚力随着基质吸力呈线性增长关系。得到了滑带土的吸力摩擦角b为13.7,有效内摩擦角有较小增长,平均有效内摩擦角15.9。     

岩石流变力学试验数据挖掘研究

介绍MSAnalysisServices的数据挖掘过程 ,分析决策树算法的基本原理。对泥板岩岩石力学的一组流变试验数据进行数据挖掘分析 ,所得结论反应出实验过程中影响岩石应变的重要因素以及它们影响力度的差异     

干湿交替对砂岩力学特性影响的试验研究

由于地下水位的升降等原因,岩体经常处于干湿交替状态,这对岩体工程的长期稳定性不利。以红砂岩为研究对象,进行了干燥－饱水干湿交替作用后的常规单轴和三轴压缩试验研究,获得了砂岩应力-应变曲线,分析了其变形破坏特征。相对于没有经过干湿交替作用的干燥试件,经过不同次数的干燥－饱水交替作用后,砂岩的弹性模量、单轴和三轴抗压强度、黏聚力、内摩擦角等都有不同程度的降低。各力学指标的总体变化趋势是在第1次饱水之后均有较大幅度的下降,此后,随着干湿交替作用次数增加其降低的幅度逐渐减小,干湿交替作用使岩石的延性增强。在围压作用下,砂岩的峰值强度均随着围压的增大而增大,干燥试件强度的围压效应要比多次干湿交替作用后的试件显著。     

Incompatible deformation in rock mechanics

Compatibility, i.e., continuous displacement field, is often taken for granted but experience teaches that rock deformation is in most cases discontinuous. The relation between incompatible deformation and continuous distribution of dislocations is established since long and is recalled in this paper. Contrary to several applications of Cosserat theory to already laminated (jointed) rock, the main goal of this paper is to give an explanation for the formation of discontinuities (joints) in rock as a result of a particular type of buckling which leads the body outside of the Euclidean space of its original configuration.     

隧道围岩中全长注浆岩石锚杆的应力分布分析

在弹性状态下,根据锚固体的受力情况建立了锚固体的摩阻力分布模型。根据此模型,结合隧道围岩位移变化函数推导了全长注浆岩石锚杆在围岩变形下的全长受力分布函数。并结合工程实例,分析了锚杆的应力分布特征,得出了注浆岩石锚杆在围岩变形中受力的基本特征。     

Finite element models for rock fracture mechanics

A finite element model for the prediction of discrete fracture propagation in rock structures loaded in compression is presented. The model integrates any one of three theories for mixed-mode fracture initiation; it contains an energy balance algorithm for predicting crack increment length, and incorporates recent developments in finite element stress-intensity factor computation. The predictions of the model are compared with the observed fracture response of a real rock structure. Results show that the model accurately predicts both stable and unstable fracture progagations observed experimentally.     

Parameter identification in a damage model for rock mechanics

Attention is focused on the mechanical behaviour of rock-like materials. Developments and applications of a constitutive model based on damage theory are presented. The internal damage model is calibrated for a hard brittle rock, Bushveld Norite, and through this process the identification of the material parameters is carried out. Emphasis is placed on the identification of the material parameters in the damage evolution law. The uniqueness of solutions in the softening regime is investigated through finite element mesh sensitivity studies of non-uniform deformation triaxial compression tests.     

非线性岩石力学问题求解的几点思考

岩石是经历多次地质构造运动形成的极为复杂的材料,高度的非线性是其本质特征之一。如何采用非线性方法对岩石力学问题研究是前瞻性的课题。本文主要工作为采用遗传算法实现了对岩石力学参数如E、μ、c、φ同时进行反演识别,结果可靠;建立径向基神经网络逼近岩石应力-应变关系代替传统的本构关系,更加符合实际,为岩石力学问题的计算,提供了新的途径;建立小波神经网络模型,可以根据具体问题的属性,自动调节网络节点数目,避免人为给定网络节点数目的弊端,使得对岩石破坏演化过程中物理量的变化的预测更加符合实际。     

New,simplified and improved interpretation of the Vaiont landslide mechanics

Both the occurrence and behaviour of the Vaiont landslide have not been satisfactorily explained previously because of difficulties arising from the assumption that the failure surface was ‘chair’ shaped. It is now known that there was no ‘chair’, which means that the 1963 landslide could not have been a reactivated ancient landslide because the residual strength of the clay interbeds would have been insufficient for stability prior to 1963. Furthermore, the moderately translational geometry reduces the influence of reservoir-induced groundwater and hence of submergence. Standard stability analyses now show that prior to 1960, the average shear strength must have significantly exceeded the peak shear strength of the clay interbeds known to have formed the majority of the failure surface. Three-dimensional stability analyses confirm these results and show that at the time of the first significant movements in 1960, the rising reservoir level had a negligible effect on the Factor of Safety. According to these results, the Vaiont landslide was most likely initiated by pore water pressures associated with transient rainfall-induced ‘perched’ groundwater above the clay layers, in combination with a smaller than hitherto assumed effect of reservoir impounding, then developed by brittle crack propagation within the clay beds, thus displaying progressive failure. Further, very heavy rainfall accelerated the process, possibly due to reservoir-induced groundwater impeding drainage of the rainwater, until the limestone beds at the northeast margin failed. With the shear strength suddenly reduced to residual throughout, the entire mass was released and was able to accelerate as observed.     

块状结构岩体力学的回顾与展望

从结构面的特性、块状结构岩体的局部稳定性、块体结构岩体的整体稳定性、块状结构岩体的力学参数、块状结构岩体渗流五个方面,简要地回顾了具有块状结构特征的岩体力学发展过程及研究现状。指出块状结构的岩体本身是一 种特殊的工程材料,不确定、非均质、各向异性、非连续、非线性是其主要特征。认为块状结构岩体力学的发展方向应进一步采用不确定性理论、现代非线性系统动力学原理与传统理论结合的研究理念。