Application of Three-Dimensional Laser Scanning and Surveying in Geological Investigation of High Rock Slope

The appearance of 3D laser scanning technology is one of the most important technology revolutions in surveying and mapping field. It can be widely used in many interrelated fields, such as engineering constructions and 3D measurements, owing to its prominent characteristics of the high efficiency and high precision. At present its application is still in the initial state, and it is quite rarely used in China, especially in geotechnical engineering and geological engineering fields. Starting with a general introduction of 3D laser scanning technology, this article studies how to apply the technology to high rock slope investigations. By way of a case study, principles and methods of quick slope documentation and occurrence measurement of discontinuities are discussed and analyzed. Analysis results show that the application of 3D laser scanning technology to geotechnical and geological engineering has a great prospect and value.

Research on Deformation and Force of Bridge Pile Foundation on High and Steep Slope in Mountainous Area

With the rapid development of my country’s economy, the demand for infrastructure construction is also increasing. However, in most areas of China, the terrains are mountainous and hilly. Some projects have to be built on steep slopes. Choosing viaducts or half-bridges on high-steep slopes is not only conducive to the protection of the surrounding environment, but also conducive to the stability of the slope. Bridges usually choose the form of pile foundation-high pier bridge. This paper uses numerical simulation to study and analyze the bridge pile foundation of the slope section. Relying on actual engineering, use the finite element software ABAQUS6.14 to establish a three-dimensional finite element model to study the bearing mechanism and mechanical characteristics of the pile foundation under vertical load, horizontal load and inclined load, discuss the influence of the nature of the soil around the pile and the stiffness of the pile body on the deformation and internal force of the bridge pile foundation in the slope section. The analysis results show that the horizontal load has a great influence on the horizontal displacement of the pile, but has a small influence on the vertical displacement, and the vertical load is just the opposite. Inclined load has obvious “p-Δ” effect. The increase in soil elastic modulus and pile stiffness will reduce the displacement of the pile foundation, but after reaching a certain range, the displacement of the pile foundation will tend to be stable. Therefore, in actual engineering, if the displacement of the pile foundation fails to meet the requirements, the hardness of the soil and the stiffness of the pile can be appropriately increased, but not blindly.

Research on Effect of Heap Loading on Deformation and Mechanical Properties of Bridge Double Pile Foundation on Steep Slope

In order to analyze the deformation and stress characteristics of the pile foundation on the slope, this paper uses the finite element software Abaqus for numerical simulation. The displacement and stress data of pile under different working conditions (the combination of heap load and vertical load and horizontal load and inclined load) were collected;the distribution of pile displacement, axial force and bending moment were analyzed. Simulation results show that: slope top loading has little effect on vertical displacement; when the heap load exceeds 200 kPa, the horizontal displacement is greatly affected. Pile axial force decreases with pile burial depth;pile lateral resistance plays a more adequate role in the rock and soil layer. The bending moment of double pile foundation is positive at the top and negative at the bottom. Applied oblique load has obvious p-Δ effect.

Earthquake-induced collapse mechanism of two types of dangerous rock masses

As the economy of China develops, an increasing number of key traffic projects have been undertaken in the west of China, where there are high, steep rock slopes. The collapse of dangerous rock masses, especially following a strong earthquake, is one of common geological disasters known in rock slope engineering. Therefore, it is important to study the collapse mechanism of dangerous rock masses induced by an earthquake and the analysis approach of its stability. This study provides a simple and convenient method to determine the collapse mechanisms of two types of dangerous rock masses （i.e. cantilever and upright） associated with the definition and calculation of the safety factor, which is based on the flexure theory of a constant-section beam by combining with the maximum tensile-stress criterion to depict the process of crack propagation caused by seismic waves. The calculation results show that there are critical crack depths in each form of the dangerous rock masses. Once the accumulated depth of the crack growth during an earthquake exceeds the critical depth, the collapse will occur. It is also demonstrated that the crack extension amount of each step is not a constant value, and is closely associated with the current accumulated crack depth. The greater the cumulative crack depth, the more easily the crack propagates. Finally, the validity and applicability of the proposed method are verified through two actual engineering examples.

露天矿高陡复杂边坡软弱岩层组“坐落-滑移式”破坏模式研究

边坡稳定性问题随露天矿开采的进行不断突出,而边坡软弱岩层严重影响边坡稳定性。大量工程实例显示,露天矿含软弱岩层组的高陡复杂边坡失稳模式通常为“坐落-滑移式”破坏。为明晰露天矿高陡复杂边坡软弱岩层组“坐落-滑移式”破坏模式的破坏机理,以某露天矿为例,提出一种针对露天矿含软弱岩层组高陡复杂边坡的综合分析方法。研究结果表明:采用工程地质分析、传统极限平衡方法和数值模拟分析相结合的综合分析方法,针对该类型复杂边坡可发挥不同分析方法的优势,较全面地从地质自然环境条件、定性定量方面、应力应变角度分析边坡破坏机理及模式,总结归纳出含软弱层组露天矿高陡复杂边坡“坐落-滑移式”破坏的“坐落-滑移-剪出”三段式破坏特征,为其他类似复杂边坡稳定性的分析和防治提供思路和手段。

基于无人机3D点云的高陡斜坡岩体结构特征

岩体结构控制着岩质斜坡的变形破坏模式,但传统的结构面信息调查方法存在危险性高、难度大的缺陷。为安全、高效地获取斜坡岩体结构信息,利用无人机摄影技术开展高陡岩质斜坡的测量,构建斜坡岩体的3D点云模型,识别结构面的产状、间距、迹长等岩体结构信息。对湖北秭归卡门子湾滑坡区调查验证,斜坡共发育6组优势结构面,平均间距为0.46~1.01 m,平均迹长为0.82~12.57 m;无人机3D点云获取的岩体结构信息精度满足要求,方法高效、可行;获得的岩体结构信息为斜坡岩体结构模型建立和稳定性评价等工作提供了可靠的数据基础。

Comprehensive Determination of Reinforcement Parameters for High Cut Slope Based on Intelligent Optimization and Numerical Analysis

High cut slopes have been widely formed due to excavation activities during the period of immigrant relocation in the reservoir area of the Three Gorges, China. Effective reinforcement meas-ures must be taken to guarantee the stability of the slopes and the safety of residents. This article pre-sents a comprehensive method for integrating particle swarm optimization （PSO） and support vector machines （SVMs）, combined with numerical analysis, to handle the determination of appropriate rein-forcement parameters, which guarantee both slope stability and lower construction costs. The relation-ship between reinforcement parameters and slope factor of safety （FOS） and construction costs is in-vestigated by numerical analysis and SVMs, PSO is adopted to determine the best SVM performance resulting in the lowest construction costs for a given FOS. This methodology is demonstrated by a prac-tical reservoir high cut slope stabilised with anti-sliding piles, which is located at the Xingshan （兴山） County of Hubei （湖北） Province, China. The determination process of reinforcement parameters is discussed profoundly, and the pile spacing, length, and section dimension are obtained. The results pro-vide a satisfactory reinforcement design, making it possible a signficant reduction in construction costs.

地震作用下桩板墙-锚索组合支护基覆型边坡的动力响应特性

地震作用下,惯性力方向对组合结构、土体、岩体的平衡状态影响显著。为深入理解桩板墙组合支护结构-基覆型边坡相互作用特性,以西南地区一隧道进口端基覆型高陡边坡为原型,开展一组简谐波加载下组合结构加固边坡的大型振动台模型试验,考虑惯性力方向对桩-土、格构锚索-坡体时程特性展开分析。结果表明:(1)惯性力作用下格构锚索-土体相互作用与桩-土相互作用表现出近似的时程一致性规律,但坡面加固结构惯性力峰值沿高程存在的相位差不可忽视。(2)结构与边坡土体的相互作用大小取决于相对惯性运动,桩-基岩相互作用由悬臂段变形状态决定。(3)惯性力达到临空面峰值,动土压力达到峰值,桩-土位移差达到正向峰值,桩身呈现外倾的主动破坏状态,锚固段前侧受力因外倾而挤压增大,因而悬臂段采用库仑主动土压力进行设计需结合桩土状态进行修正。(4)简谐波作用下,坡体惯性力及变形是组合支挡结构沿高程受力分布特性的关键因素,组合结构设计时需重点关注坡脚应力集中区及坡顶惯性力放大区。本研究可为组合结构抗震加固设计提供理论支撑。

基于无人机摄影测量技术的高陡边坡危岩体特征构建与分析

在高陡边坡的危岩体调查中,受限于调查人员可到达的范围,难以获取危岩体的特征参数,从而影响危岩体的稳定性判别。无人机摄影测量技术能够安全、快速、全面、精准的获取危岩体的特征信息。本文以鸡冠岭崩塌隐患为例,利用无人机摄影测量技术获取坡面高精度影像,通过提取点云数据构建三维模型,基于最小二乘法完成平面拟合获取危岩体的体积及结构面产状信息,并结合实际测量数据,采用赤平极射投影法和极限平衡法定性和定量评价危岩体的稳定性。经过分析计算,鸡冠岭崩塌四处主要危岩体的体积分别为102.86 m^(3)、355.27 m^(3)、236.60 m^(3)和454.91 m^(3),根据定性分析和定量计算,危岩体均为欠稳定状态。通过本文的实践,体现了无人机摄影测量技术在识别高位隐蔽危岩体方面的优势,对于发展基于无人机摄影测量技术定量判定危岩体的稳定性方面具有借鉴意义。

基于无人机贴近摄影测量的露天采石场高陡岩质边坡岩体结构面信息自动识别

岩体结构面的识别与解译在露天采石场岩质边坡稳定性分析中具有重要意义,对于高陡岩质边坡而言,传统的勘察手段效率低且危险性高,无人机倾斜摄影测量生成的高陡岩质边坡三维实景建模精度低且自动解译困难。提出了一种基于无人机贴近摄影测量的高陡岩质边坡岩体结构面信息的精细化调查方案,并在武汉市东湖高新技术开发区长岭山露天采石场崩塌地质灾害调查中完成了实例应用,该方法使用大疆M300 RTK无人机搭载DJI P1相机完成倾斜摄影测量与贴近摄影测量工作,建立高精度的露天采石场高陡岩质边坡的实景三维模型和高密度三维点云,通过区域生长算法自动解译其岩体结构信息。结果表明:采用本文方法进行岩体结构面调查所提取到的信息准确度高、可视化效果好,且计算效率高,可为类似边坡实际地质灾害调查与防治提供依据。

四川巴塘水电站两洞进口高边坡加固措施研究

高边坡的稳定性及治理问题是重大工程建设中的首要考虑的工程地质和岩石力学问题,控制着工程建设的可行性和经济性。笔者以巴塘水电站两洞进口高边坡的治理为例,结合具体工程地质情况,分析了该工程倾倒变形岩体参数取值及抗滑稳定性,根据分析结果,采取了固结灌浆并插钢筋束后再进行隧洞开挖挂口等措施,联合加固高边坡。该措施满足设计要求,并在工程实践中证明了该方法的可行性与经济性,效果较为显著。

超厚中风化层高陡边坡稳定性研究

风化作用使岩石强度降低,进而导致边坡岩体的力学性能大幅度下降,因此露天矿山高陡边坡主要以微风化岩体为主,而以中风化岩体为主的边坡通常设计较为平缓,高度也多为30~50 m。对某钼矿完整性好的超厚中风化层高陡边坡稳定性进行研究,采用极限平衡法计算爆破振动力作用下的边坡安全系数,并根据计算结果对边坡参数进行优化,为下一步的设计提供技术支持。结果表明:边坡稳定性主要受到岩石强度和岩体完整性2个方面因素的影响,深部的中风化层如果节理裂隙发育减少,岩体完整性提升,边坡的稳定性也得到改善,完整性好的超厚中风化层也可以设计为高陡边坡。

临岩堆边坡填方高速公路稳定性评价研究

西南地区地质条件较差,广泛存在松散岩堆边坡,天然岩堆呈极限平衡状态,具有潜在失稳风险。在岩堆边坡新建填路,在外力作用下岩堆边坡极限平衡打破,填方道路可能出现失稳,填方边坡薄弱面发生局部或整体滑动,威胁高速公路工程建设。本文以云南岩堆边坡填方高速公路为典型实例,通过收集资料岩堆内部沉积结构特征,反演分析岩堆边坡稳定状态和参数,进一步分析运用数值模拟分析得到填方道路稳定性与变形破坏之间的关系,验证了加固岩堆边坡填方道路稳定特性,证明施工方案的可靠性。

植被混凝土护坡技术在高陡岩石边坡生态防护中的应用

在我国,由于地理环境和气候条件具备多样性,边坡稳定性问题尤为突出。因此,研究边坡稳定技术尤其是生态防护技术,具有重要的理论意义和实际价值。植被混凝土护坡技术是一种将混凝土与植被相结合的护坡技术,既能保证边坡的稳定性,又能实现生态防护。文章概述了植被混凝土护坡技术,并结合实际案例,探析了植被混凝土护坡技术在高陡岩石边坡生态防护中的应用。

基于微震的溪洛渡拱坝右岸变形规律探究

随着我国对水资源的大力开发,大批水电站正在建设,其中一部分已经投入使用,这些水电站都伴随着高陡的岩质边坡,使得边坡的稳定性问题尤为突出,因此对蓄水期岩质高边坡的变形破坏特征以及稳定性问题的分析研究就变得非常重要。笔者通过对溪洛渡水电站蓄水期右岸边坡进行微震监测和数值模拟计算,揭示了右岸边坡深部岩体的微震事件所处岩层,分析研究了右岸边坡应力和位移与蓄水位的关系特征,在蓄水加载过程及泄水卸载过程中,微震事件均主要分布在上游围堰至下游二道坝之间右岸坝基下方深部阳新灰岩层中,玄武岩地层中分布较少,判断溪洛渡水电站大坝坝基在蓄水过程中出现局部岩体应力集中和应力迁移现象。

西瓦里克地质区域条件下软岩高边坡施工技术

以尼泊尔某水电工程引水隧道TBM始发平台永久边坡工程为依托,介绍西瓦里克地质区域条件下软岩高边坡的设计方案与施工关键技术,通过稳定性计算,采用土钉锚杆+网格梁/喷锚支护+综合排水措施。通过施工监测结合永久监测数据分析,边坡整体稳定,满足设计要求。

无人机倾斜摄影技术在高陡边坡危岩体识别及稳定性评价中的应用

无人机倾斜摄影技术凭借高精度、多视角还原真实地貌的能力,已在地形地貌测绘、城市三维建模、工程勘察建设、土地利用规划等领域得到了广泛的应用。本文采用无人机倾斜摄影+遥感综合解译+落石轨迹模拟的综合研究评价方法,基于西藏某新建公路两侧高陡边坡实景三维倾斜模型,对该区域发育的危岩体开展了详细的解译分析,共识别危岩体67处,通过稳定性及其对下方公路威胁性分析,得出危岩体对该区域西侧中部、北侧坡面东部及南侧坡脚部分区域具有明显威胁性,易对公路来往行人及车辆造成危害。研究成果为现场危岩体清理、防护治理提供了重要的技术依据,有效弥补了现场人员无法到达、勘察作业困难的缺陷,具有重要的理论及实际意义。

控制断层作用下高陡岩质边坡稳定性分析——以昭通市红石岩边坡为例

高陡岩质边坡的稳定性分析和治理措施是工程建设和防灾减灾中亟需重视的问题。其存在岩层变化复杂,受节理、断层等结构面控制等特点。依托昭通市红石岩高陡岩质边坡工程勘察资料为地质背景,采用离散元数值模拟软件UDEC构建边坡模型,在坡体上下两个崩塌区及断层处布置监测点,通过对比是否存在断层两种工况下的位移量分布、应力分布,分析边坡中部控制断层对高陡岩质边坡失稳破坏特征的影响,提出边坡防治措施的参考依据。结果表明:位移量以控制断层为分界线,断层上部岩体在迭代过程中位移量明显大于下部岩体;断层存在对应力大小分布没有明显影响,而对应力方向具有较大影响,无断层时应力主要朝向水平,有断层时主要朝向竖直。

某锰矿露天废石场边坡稳定性评价及高陡边坡防治

矿山开采工作的地质变化容易导致地质灾害的发生,进而影响周边人们的生产生活。针对锰矿露天废石场的高陡边坡问题,利用极限平衡分析法对岩土体进行物理力学参数的分析,以分析滑坡面的受力状况及边坡稳定性因素。再使用三维快速拉格朗日分析法,并结合废石场设计图纸的数值,生成三维集合建模以分析滑坡面的边坡角和堆置高度。结果显示,圆弧形滑坡面在自重和地震作用中,整体安全系数下降20.21%~20.48%,沿基底接触面滑动安全系数降低18.56%~19.75%。废石场堆置高度的不断变化和边坡临界值的计算,得出合理边坡角为29°。为高陡边坡防治的治理方案提供技术参考。

乌长高速金旗特大桥高陡岸坡稳定性分析研究

贵州省乌长高速公路金旗特大桥跨越猫跳河,两岸岸坡危岩体及崩塌堆积体等不良地质条件较发育,严重影响桥梁选址及其安全。为研究该桥高陡岸坡的稳定性,该文通过空天地一体化综合勘察,查明了桥址区主要不良地质条件。结合数值分析及InSAR等技术手段,定量表征了岸坡危岩体的运动威胁范围,阐明了岸坡堆积体在内外动力作用下的稳定性及变形失稳模式。结果表明:①桥址区不良地质主要表现为陡崖卸荷带、危岩体和崩塌堆积体,危岩体的失稳破坏模式为拉裂‒倾倒式;②W1、W3和W4危岩体失稳后的运动距离分别为65 m、57 m和320 m,影响乌当岸桥台和长顺岸桥墩;③乌当岸坡堆积体在天然、降雨、降雨+地震3种工况下均处于稳定状态;长顺岸坡堆积体在天然和降雨条件下较稳定,在降雨+地震工况下上部堆积体与基岩接触面处剪切塑性区完全贯通,处于不稳定状态,其失稳破坏模式为蠕滑‒拉裂式。该研究结果可为贵州省深切峡谷及陡崖地区桥梁高陡岸坡的综合勘察和稳定性分析提供参考和借鉴。