强震区挡土墙结构的稳定问题备受关注,从重力式挡土墙抗倾覆和抗滑移可靠性分析角度出发,将地震作用视为计算墙后主动土压力时对土体重度和内摩擦角进行修正的参数——地震修正角θ.将θ与墙后土体的黏聚力c和内摩擦角φ作为随机变量,以此建立了考虑地震作用的挡土墙抗倾覆和抗滑移功能函数.通过蒙特卡罗法分别计算了考虑变量呈不同统计特性的挡土墙失效概率,研究变量统计特性对挡土墙抗倾覆和抗滑移可靠性的影响.结果表明:墙后土体c与φ的相关系数ρcφ逐渐增大时,挡土墙抗倾覆和抗滑移的失效概率相应增加,尤其是c与φ负相关时,挡土墙失效概率对ρcφ的变化更为敏感;将θ视为常数或忽略θ与c和φ的相关性时得出的失效概率偏小,会导致对挡土墙稳定性做出偏安全的估计;θ与c、φ的相关系数ρθc和ρθφ增大时,挡土墙的抗倾覆及抗滑移失效概率整体呈减小趋势;变量参数间相关性对挡土墙可靠性均有影响,其中ρcφ影响最敏感,ρθc次之,ρθφ影响最小.

为了了解土石混合体的破坏机理及其力学性能,借助于PFC数值模拟试验,研究了土石混合体的剪切特性,包括不同颗粒级配组粒径质量分数、颗粒的缺失、模型尺寸3个因素对剪切强度的影响。研究结果表明:(1)细颗粒含量对模型剪切强度的大小起

常规砂浆无法满足反倾斜裂隙和缺陷的工程填充要求，在注浆压力驱使下会引入大量气泡，浆液密实度得不到保障。针对此，研发了一种新型磁性环氧树脂水泥浆液（MEC），可实现反重力式注浆锚固、导向式流动、增大浆体密实度、浆液粘度实时调控。采用XRD、SEM、N 2 吸附测试方法，对MEC浆液在不同磁场作用下的微观形貌、水化产物和孔径进行了分析。结果表明：MEC浆液主要分为环氧树脂固化、水泥水化2个硬化过程。固化产物对水化产物进行包裹，与AFt和Ca（OH） 2 中的Ca^2+ 发生离子作用，形成络合物包裹磁粉，对浆液中存在的微小孔隙进行填充；磁场强度由400GS增大到6000GS时，孔隙面积减小率达77.6%，孔隙数量减小率达76.8%。N 2 吸附试验表明，附加磁场会降低介孔和大孔的数量，显著减小比表面积，磁性浆液符合H 4 型滞回线，主要表现为墨水瓶孔；基于磁偶极子理论，数值模拟了磁颗粒受力，分析结果表明在磁场强度为2000～6000GS可高效减小孔隙面积。

岩体结构面粗糙度的量化表征一直是岩土工程领域关注的焦点问题。在以往表征方法基础上,结合结构面三维形貌特征扫描分析,综合考虑结构面的层次结构特征,提出采用平均起伏角和平均相对起伏幅度表征一级波状起伏结构,采用面积扩展率表征结构面次级细微粗糙结构,并分析建立了结构面三维粗糙度系数与形貌参数的相关关系。验证分析表明,论文提出的结构面三维粗糙度表征方法可以较好地兼顾结构面一级波状起伏结构特征和次级细微粗糙结构的影响,计算得到的结构面抗剪强度与试验值吻合较好。相关研究结果可为结构面粗糙度量化分析及抗剪性能估算提供较好的借鉴。

Aiming at solving the problems of physical model visibility and repeatability in natural rough rock fracture seepage tests, the method of determining the additive ratio of rock-like materials by using natural rock elastic modulus as the target variable was put forward and a transparent resin fracture model that matched perfectly with the original fracture surface was fabricated. A visual seepage test device that could accurately obtain the seepage area, flow path, and velocity vectors from the mesoscopic perspective was developed. After processing the test video at the millisecond level, the flow velocity was calculated by using the method of layer superposition to draw the flow velocity vector graph. The results showed that the water flow in a filled fracture had a significant nonlinear spatiotemporal evolution phenomenon. At the same time, the mapping results with the roughness contour map were combined to show that the dominant seepage channels are mainly distributed in the region with JRC values of 0 similar to 4.0. The water in the fracture accelerates and gathers along the main flow path at fracture dip angles of 60-90 degrees, which proves that the low roughness area is the dominant seepage channel. A new idea of measuring fracture aperture was put up, which was to measure the fracture apertures of any point on the flow path by using bubbles through digital image processing technology. It was found that the average aperture could be obtained precisely by calculating the area of the actual seepage area. The above research can provide a new method for the study of fracture seepage characteristics and the measurement technology of fracture apertures in the laboratory.

The hydro-fluctuation belt is the most sensitive part of the reservoir bank slope. The rock mass in the hydro-fluctuation belt has been affected by the cyclic dry-wet process. The water infiltrates into the rock mass through its pores and cracks. Through time, the cyclic dry-wet process is posing a significant impact on the evolution and seepage characteristics of jointed sandstone. In this paper, a series of tests such as seepage test, scanning test of the joint surface morphology, and measurement test of ion concentration were conducted to investigate the impact of the cyclic dry-wet condition on a single-jointed sandstone. The following conclusions were made based on the experimental results: (1) There is a positive correlation between the hydraulic conductivity (k(f)) and the number of dry-wet cycles (n). Initially, the trend was steep. Gradually, it reached a plateau. (2) The fractal dimension D was slightly decreasing when the number of dry-wet cycles increased. A considerable drop in the fractal dimension was observed within the first eighth dry-wet cycles. (3) A negative correlation between the hydraulic conductivity and the fractal dimension was established by the logistic model with four parameters. (4) On the one hand, calcareous cement was dissolved and disintegrated by the water. On the other hand, feldspar minerals underwent physical and chemical reactions. In the meantime, the water-rock interaction altered the ion concentrations, microstructures, and the permeability of sandstone. The findings of this paper provide a theoretical basis for the stabilization of the reservoir bank slope.

鉴于重庆市奉节县藕塘滑坡地区土石混合体是一种非均质、非连续的地质体,力学性质复杂,对比分析了影响土石混合体强度特性的因素,发现试样剪切应力-剪切位移曲线的光滑程度不仅与试样点高程有关,还与试样的含水率有很大关系;随着试验点

高面板堆石坝面板变形监测一直是坝工界的一个技术难题,常规仪器难以处理此问题。对此提出一种基于MEMS三轴陀螺仪和三轴加速度计的微惯性监测系统,用于大坝面板挠度变形监测。与旧监测系统相比,新监测系统成本更低,精度更高。对新监测系统的具体组成,监测原理进行了阐述。同时,为提高测量精度,采用无损卡尔曼滤波对监测信号进行处理。实验证明,无损卡尔曼滤波算法有效提高姿态解算的精度。将新监测系统用于猴子岩大坝面板挠度测量,并与FOG监测系统进行对比,结果表明,新监测系统的测量数据能够真实反映面板变形,且精度较高。

新型弱光纤阵列分布式测量技术是大坝渗流监测的新技术。根据弱光纤光栅测温原理、对流传热方程组和牛顿冷却公式,推导出热光纤渗流监测理论公式。设计了基于加热弱光纤监测渗流的圆筒模型试验,通过光纤周围温度场与渗流场的耦合关系,间接获得圆筒模型的渗流状态。试验结果表明,温度边界层是影响温度场和渗流场的重要因素,渗流水温度对温度边界层影响较大;渗流量与温差ΔT的线性度高;渗流流速u在0.02～0.08cm/s时与ΔT/θ（θ为光纤测量温度与渗流水温度之差）拟合关系式的各项系数与理论推导公式相近。

基于正交试验的细观参数标定方法,建立了平行黏结模型中砂岩材料宏细观参数之间的关系.首先设计了单轴压缩平行黏结模型的7个细观参数正交试验方案,其次对各方案进行了颗粒流数值模拟试验,最后对试验结果进行了多因素方差分析和线性回归分析,确定了各细观参数对宏观参数的影响及其排序,最终建立了宏细观参数之间的关系.以3组砂岩室内试验验证了所提方法的有效性.结果表明:利用标定的细观参数进行颗粒流数值试验,得到的宏观参数与室内试验结果较为吻合,表明通过正交试验设计法标定的砂岩细观参数是可靠的.