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1.
五强溪水电站左岸船闸边坡开挖监控设计的理论与实践 总被引：12，自引：7，他引：12
五强溪水电站船闸左岸边坡，是由前震旦系的Ｐｔ１（主要为千枚状板岩）和Ｐｔ２（主要为砂岩、板岩）组成。因断层穿插，岩体破碎，边坡稳定性很差。为确保边坡在开挖施工期的安全，作者根据工程地质力学和系统科学相结合的方法，对之进行监控设计，取得了成功。 相似文献
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三峡永久船闸是长江三峡水利枢纽工程三大主体工程之一，保证船闸高边坡施工和运行期间的稳定，为该工程的重大技术问题，对此，提出了一系列开挖施工方案及加固处理措施，并运用实践中。 相似文献
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通过相邻两个时间区间位移观测结果均值差分的积分描述和Harr小波基函数的小波变换方程的对比分析,得到了一个将不同时间尺度下边坡位移均值变化表示为相应尺度下小波变换系数的基本关系。根据这一关系,提出了可以采用小波变换方法确定两个相邻时间区间位移均值在不同时间尺度下变化规律的边坡位移演化的多尺度分析方法。针对卧龙寺新滑坡、三峡永久船闸边坡开挖和隔河岩水电站进水口边坡变形的观测结果,讨论了它们的位移演化多尺度特征。当边坡位移呈现较规则的变化趋势时,在一个尺度上就可以提取它们的时间演化特征。开挖剧烈扰动的影响可以通过给定时间尺度支撑区端点与位移突变点之间递增连的线进行近似。 相似文献
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The Feedback Analysis of Excavated Rock Slope 总被引：5，自引：0，他引：5
Summary In this paper a methodology of the feedback analysis on the mechanical parameters and stability of the slope excavated in
rock masses is presented. The method is based on the combination of the elasto-viscoplastic finite element method and the
complex shape minimum method. Special attention has been paid to the simulation of the variation of parameters because of
the blasting damage and the stress relief relaxation, and the de-coupling of parameters as well. The slope excavated in the
granite rock masses situated at the ship lock of the Three Gorges Project is studied, from which the mechanical parameters
of the rock masses and the deformation, as well as the stability of the rock slope are forecasted in time as the going on
of the slope excavation. 相似文献
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Analysis of Critical Excavation Depth for a Jointed Rock Slope Using a Face-to-Face Discrete Element Method 总被引：1，自引：0，他引：1
Summary The critical excavation depth of a jointed rock slope is an important problem in rock engineering. This paper studies the
critical excavation depth for two idealized jointed rock slopes by employing a face-to-face discrete element method (DEM).
The DEM is based on the discontinuity analysis which can consider anisotropic and discontinuous deformations due to joints
and their orientations. It uses four lump-points at each surface of rock blocks to describe their interactions. The relationship
between the critical excavation depth D
s
and the natural slope angle α, the joint inclination angle θ as well as the strength parameters of the joints c
r
,φ
r
is analyzed, and the critical excavation depth obtained with this DEM and the limit equilibrium method (LEM) is compared.
Furthermore, effects of joints on the failure modes are compared between DEM simulations and experimental observations. It
is found that the DEM predicts a lower critical excavation depth than the LEM if the joint structures in the rock mass are
not ignored. 相似文献
8.
三峡永久船闸变形监控指标的研究 总被引：1，自引：0，他引：1
本文采用变形速率法,对三峡永久船闸变监控指标进行探索。通过比较手施工反馈的结果,证明了加固的效果,说明了三峡永久船闸体整体是稳定的。 相似文献
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基于反映裂隙岩体渗透张量各向异性特性的广义达西定律与相对透水率等裂隙岩体渗流基本理论,应用三维非线性有限元方法,对长江三峡工程永久船闸高陡边坡在连续降雨条件下裂隙岩体饱和-非饱和、非恒定渗流扩散过程进行了三维数值仿真分析,得出了连续降雨条件下船闸高陡边坡裂隙岩体渗流场的时空分布规律及典型降雨时段闸室混凝土衬砌上的最不利外水压力荷载,对暴雨入渗情况下闸室边墙稳定性与安全性进行了评价。分析结果表明,闸室混凝土衬砌具有较高的安全度;船闸高陡边坡内排水系统效果显著,即使遭遇长期强降雨,闸室衬砌上的外水压力荷载受降雨的影响也不大。 相似文献
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Slope mass rating (SMR) is a commonly used geomechanical classification for the characterization of rock slopes. SMR is computed adding to basic rock mass rating (RMR) index, calculated by characteristic values of the rock mass, several correction factors depending of the discontinuity–slope parallelism, the discontinuity dip, the relative dip between discontinuity and slope and the employed excavation method. In this work a graphical method based on the stereographic representation of the discontinuities and the slope to obtain correction parameters of the SMR (F1, F2 and F3) is presented. This method allows the SMR correction factors to be easily obtained for a simple slope or for several practical applications as linear infrastructures slopes, open pit mining or trench excavations. 相似文献
13.
西南某大型水电站拱肩槽边坡开挖的变形响应研究 总被引：1，自引：0，他引：1
对在复杂地质条件和高地应力环境下,高达近330m的人工岩石拱肩槽高边坡的研究,尤其是在大坡比、强开挖条件下所表现的变形响应规律的研究具有重要的理论与现实意义。论文通过大量现场跟踪施工的地质调查工作和利用丰富的监测资料的基础上,系统地研究了此类边坡变形响应的基本规律及特殊表现,得到了拱肩槽高边坡开挖过程中,边坡的变形与开挖过程有较强的同步性。变形主要受开挖卸荷影响;随开挖的进行,坡体的变形随开挖面的远离表现出总体衰减的特征等。开挖后的坡体的变形量较小,变形深度较浅,而且在开挖12~18个月后,变形趋于稳定。这些结论对类似边坡开挖及其稳定性的控制具有重要的借鉴意义。 相似文献
14.
Wang Yufeng Wu Li Cheng Yao Huang Zhigang 《Geotechnical and Geological Engineering》2021,39(5):3517-3531
Two expanding excavation schemes, Bench Expanding excavation Method (BEM) and Double-Straight Wall with 6-parts expanding excavation Method (DSW-6 M), were designed for the expanding excavation project in Loushan Tunnel in the soft surrounding rock section. The 3D finite-difference model was used to analyze the surrounding rock deformation and Ground Surface Settlement (GSS) caused by adopting different excavation schemes. The influence of non-uniform GSS on inclination of the High-Voltage Tower and the surrounding rock stat during expanding excavation were compared and analyzed by adopting different schemes. The results shown that DSW-6 M based on settlement control was better than BEM, and the reasons were analyzed by surrounding rock stat during construction. DSW-6 M was adopted in actual construction. The settlement prediction was in good agreement with the measured results. The rules between increasing rate of vault settlement and surface slope was obtained by analyzing the field monitoring data.
相似文献15.
Jeanette M. Cosden 《Geochimica et cosmochimica acta》2003,67(7):1331-1338
Comparative observations of PdII and PtII hydrolysis in chloride solutions indicate that [PdCl3OH2−]/[PdCl42−] and [PtCl3OH2−]/[PtCl42−] concentration ratios in salinity 35 seawater (S = 35) are smaller than one at a typical surface ocean pH (∼8.2), and are larger than one at pH = 8.2 when S < 10. The hydrolysis behaviors of PdCl42− and PtCl42− are very similar. In 0.5 M NaCl at 25°C the hydrolysis constant for both elements, written in the form β1 = [MCl3OH2−][Cl−][H+][MCl42−]−1, is logβ1*=−8.97. Between ionic strengths 0.3 M and 1.0 M for PdII and between 0.1 M and 1.0 M for PtII, log β1 is within approximately 0.1 units of the value appropriate to 0.5 M NaCl. This small dependence of PdCl42− and PtCl42− hydrolysis constants on ionic strength is consistent with predictions based on expected activity coefficient behavior.Carbonate is observed to complex PdCl42− significantly, but to a smaller extent than OH− under conditions appropriate to seawater. Complexation of PtCl42− by CO32− was observed in this work but the rate of complexation was too slow to allow equilibrium observations. The principal dissimilarity between the chemistries of PdII and PtII in our investigation was the sharp contrast in observed PdII and PtII reaction rates. Differences in reaction kinetics may cause fractionation of PdII and PtII in the environment. The speciation of PtII, unlike PdII, is likely to be based on chemical environments experienced by PtII over a period of days, and perhaps weeks. 相似文献
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现有上硬下软边坡的研究大都集中在压缩挤出变形的近水平泥岩、页岩基座型边坡变形演化过程,针对倾倒变形的板岩基座型边坡开挖响应研究甚少,本文以西藏玉曲河某水电站厂址边坡为研究对象,根据现场地质调查建立符合坡体实际情况的地质结构模型,采用物理试验的方法模拟原型边坡开挖。通过试验揭示上硬下软反倾边坡在开挖条件下的变形响应特征及破坏模式。研究结果表明:（1）开挖条件下上硬下软型边坡变形破坏过程分为a）下部软岩倾倒弯曲加剧;b）软岩倾倒折断,上部卸荷硬岩沿已有裂隙剪切;c）倾倒软岩滑移,卸荷硬岩剪断岩性分界部位,折断面贯通3个阶段。其变形破坏模式为下部软岩倾倒—上部硬岩剪断组合滑移型破坏;（2）开挖强倾倒区岩体会使下部软岩迅速失稳并促使上部硬岩剪切破坏;开挖引起的反倾上硬下软边坡大变形在短时间内完成,前期变形和能量积累是一个较长的过程;（3）开挖时需避免对坡脚倾倒岩体“大开挖”施工。 相似文献
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考虑到边坡工程涉及到众多的不确定性因素,本文提出一种岩质边坡稳定性分析及可靠度评价方法。此方法包括地质勘探和试验规划、地质和力学模型的研究、确定初始边坡设计方案、边坡稳定性分析及稳定性可靠度评价,此方法已应用于龙滩水电站船闸高边坡的稳定性分析,据此提出边坡的设计方案为工程单位采用。 相似文献
18.
基坑开挖对邻近铁路路基变形影响与控制 总被引：1，自引：0，他引：1
以某紧邻既有铁路线的基坑工程为依托,基于现场实测数据,分析了路基与基坑的变形规律、沉降原因和控制措施。结果表明,受列车荷载与渗漏水影响,路基沉降在坑底旋喷加固和施工冠梁、混凝土撑期间迅速增加,形成了长约50 m、最大沉降95 mm的沉降槽,60%以上的路基在该阶段的沉降增量占阶段累计沉降的70%以上,而地表沉降多小于20 mm,约为开挖深度的2.4‰;路基沉降槽处坑外横断面地表沉降呈“凹槽形”,在路基处沉降最大。在坡顶进行双液注浆能够控制地表与路基沉降,减少后续开挖施工对路基的影响,但注浆施工易导致边坡变形突变,尤其是向坑内的水平位移,不利于边坡稳定和铁路安全。 相似文献
19.
三峡船闸高边坡预应力锚固施工技术 总被引：1，自引：0，他引：1
邹俊 《中国地质灾害与防治学报》2004,15(2):98-103
三峡船闸是目前世界上规模最大、水头最高、结构最复杂的船闸，人工开挖边坡最大高度170m，下部直立坡最大高度67．8m，地质条件相对较复杂，直立岩壁上有大小l000多个不稳定块体出露。锚固工程是保证施工安全和结构安全的主要措施，预应力锚固一般为水平孔、多为3000kN级，孔深索长30～57m，数量多、技术要求高，施工作业条件差，施工干扰多。施工中针对系列技术难题，进行了试验攻关。文章介绍了长江三峡船闸锚固工程的设计情况和施工技术难题。重点介绍了钻机的改造，水平锚固孔防斜保直钻进工艺、锚固孔测斜技术，水平孔止浆措施及编索、下索等方面的各项技术措施和施工干扰的协调处理。通过锚索测力计、岩体变形等观测资料表明工程岩体及边坡稳定，一整套预应力锚固技术工艺创新，达到了预期效果，经验可供参考。 相似文献