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1.
Francesca de Rienzo Pierpaolo Oreste Sebastiano Pelizza 《Geotechnical and Geological Engineering》2009,27(4):539-547
This paper introduces a 3D geological and geotechnical model of the subsoil of the city of Turin managed by means of a Geographical
Information System (GIS). The 3D GIS of the subsoil of Turin represents a useful decision-support tool in the underground
management for engineering purposes and it’s here proposed as base geological elaborate to support future underground work
in the city. In the final part of the paper, an application of the information coming from the 3D model is shown to define
the characteristics of the optimal excavation machines (the type and disposition of tools on the head and the necessary engine
power) for the future developments of the Underground Metro System. 相似文献
2.
The finding of a remarkable number of stratigraphies from mechanical surveys and water research wells, drilled in the urban
area of Turin over the last few decades, has made it possible to reconstruct the geology of the subsoil in great detail. In
particular, it has been possible to define the distribution of the cementation in the Quaternary alluvial sediments through
geological planimetries that refer to different depths from the ground level. The cementation map of the Turin subsoil can
be considered very useful for the planning of future underground works and for the definition of the necessary construction
methods. An accurate mineralogical analysis has identified a “meniscus” type structure of the cementation; this leads us to
believe that the cementation has formed in a vadose environment. The reason for the precipitation of the calcium carbonates
is therefore probably due to infiltration of the slightly acidic meteoric water into the subsoil and not to the mixing of
water with different temperatures, hardness and pH values, as some authors believed in the past. 相似文献
3.
断层构造是制约地下工程设计与施工的关键因素。综合考虑复杂地质构造与地下洞室群结构的耦合关系,采用三维地质建模方法建立实现了地层体、断层体与地下洞室群结构的统一模型。基于三维模型提出了断层复杂度的概念,为水利水电工程地下厂房洞室群的选址方案分析提供了一种新的手段。针对地下围岩稳定性问题,提出基于断层与断层、断层与开挖面相互切割的曲面块体识别方法,搜索地下厂房洞室群内可能的失稳区域。上述方法已成功应用在某水电工程地下厂房洞室群分析中,在设计方案优化分析中取得了良好的效果。 相似文献
4.
For long deep tunnels as currently under construction through the Alps, mechanized excavation using tunnel boring machines (TBMs) contributes significantly to savings in construction time and costs. Questions are, however, posed due to the severe ground conditions which are in cases anticipated or encountered along the main tunnel alignment. A major geological hazard is the squeezing of weak rocks, but also brittle failure can represent a significant problem. For the design of mechanized tunnelling in such conditions, the complex interaction between the rock mass, the tunnel machine, its system components, and the tunnel support need to be analysed in detail and this can be carried out by three-dimensional (3D) models including all these components. However, the state-of-the-art shows that very few fully 3D models for mechanical deep tunnel excavation in rock have been developed so far. A completely three-dimensional simulator of mechanised tunnel excavation is presented in this paper. The TBM of reference is a technologically advanced double shield TBM designed to cope with both conditions. Design analyses with reference to spalling hazard along the Brenner and squeezing along the Lyon–Turin Base Tunnel are discussed. 相似文献
5.
工程区域地质条件是影响地下洞室群稳定的重要因素,而通用数值分析软件在建立复杂地质模型时存在建模时间长、准确度低、不能真实反映复杂地质特征等困难。针对此问题,采用以非均匀有理B样条（NURBS)为主的混合数据结构,对复杂区域地质构造进行了三维建模,建立了西南某水电站大型地下洞室群的三维地质模型。并以此模型为基础,建立了包括空间曲面断层、地层等复杂地质因素的数值模型,结合ABAQUS的隐式和显式分析,对洞室开挖和地震作用下的动力时程响应进行了仿真分析。分析结果表明,该方法不仅较大程度地反映了实际地质情况,而且有利于数值仿真分析的网格剖分与计算,从而为分析地下洞室群地震反应提供了三维数值模型,为地震作用下洞室的安全性评价提供了重要的技术支持。 相似文献
6.
Stefania Sica Angelo Dello Russo Federica Rotili Armando Lucio Simonelli 《Natural Hazards》2014,71(3):1913-1935
Subsurface cavities or stiff inclusions represent mechanical discontinuities for seismic waves propagating in soils. They modify the propagation pattern of seismic waves and alter soil response in correspondence to the ground level or building foundations. In the literature, different analytical and numerical solutions have been proposed to account for the effect of underground cavities or inclusions on the motion generated by P, S or R waves. In these former studies, the subsoil was assimilated to a homogeneous, isotropic and linear elastic halfspace containing one or more cavities. In the present study, the effect of subsurface cavities on ground motion amplification has been analysed accounting for soil stiffness degradation and associated damping increase with increasing levels of shear strains, a fundamental aspect of soil behaviour under earthquakes. The analysed model was inspired to a real case represented by the village of Castelnuovo (Italy), which during the 2009 Abruzzo earthquake suffered huge damage. The main shock (6 April 2009) caused the collapse of 50 % of the whole built environment. The historical centre of Castelnuovo rises on a hill. In its subsoil, there are many cavities with roofs 2–3 m below the ground level. The longitudinal NW–SE section of the hill has been investigated by 2D nonlinear site response analyses. A preliminary site response analysis was performed without modelling cavities, to identify ground motion amplification due to mere stratigraphic and topographic factors. The numerical model was later refined inserting: (1) a single cavity below the hilltop, (2) multiple cavities placed below the ground surface of the hill and (3) multiple cavities filled with concrete (inclusions). The performed study highlights the important role exerted by underground cavities on the ground motion computed at the hill surface. This effect should be properly considered for both microzonation studies and the correct determination of the seismic actions on specific buildings. 相似文献
7.
The current interest in the potential utilization of subsurface space for the storage of a wide variety of materials is responsive to the increasing pressures of environmental concerns, particularly as it applies to the development of urban or suburban space. These pressures, in conjunction with the continuing development of underground excavation technology, combine to provide a situation within which the concept of subsurface space utilization is becoming increasingly attractive relative to more conventional surface developments. Underground pumped storage is currently an economically viable alternative to the conventional above ground type of facility, and is made increasingly attractive by consideration of the reduced environmental impact, which the underground concept make possible. This paper is intended to provide an introduction to the engineering challenges of underground pumped storage, with particular reference to a limestone mine located some 671m below the ground surface and having a volume of 9.6 million m3. To this end, the paper presents the numerical modeling and analyses to establish a powerhouse setting that would provide both a structurally stable excavation under the loading conditions imposed by the high-pressure brine, and eliminate the possibility of significant brine inflow to the excavated caverns. 相似文献
8.
9.
Daniela Ruberti Marco Vigliotti Rossana Marzaioli Annamaria Pacifico Antonella Ermice 《Environmental Earth Sciences》2014,71(1):319-339
This study attempts to assess the aquifer vulnerability in the northeastern sector of the Campania Plain (southern Italy). The area is a highly populated region with anthropic impacts caused by rapid urban growth, quarrying, agricultural and industrial activities and uncontrolled waste storage. The main geologic feature of this plain is the alternation of alluvial/transitional and volcaniclastic deposits of Late Pleistocene–Holocene age. The study was performed integrating different sets of geologic and environmental data to restore the stratigraphic architecture and to assess anthropic impacts on subsoil. The reconstruction of stratigraphic subsurface architecture was based on remarkable geodatabase, concerning well log stratigraphies. Specific insights have been delineated on the volcaniclastic lithofacies heteropies across the entire area of study to highlight the differences in lithification degree and permeability. The contribution of pedogenesis on the reconstruction of the stratigraphic setting was also considered for the relative implications on groundwater quality concerns, as paleosols are usually regarded as aquitards. All of this information has been managed into a GIS project to produce a detailed 3D geological reconstruction, integrated with hydrogeological information to provide a model of the aquifer under study, highlighting sites of greater vulnerability to pollution. The anthropic impacts on subsoil were assessed by evaluating land-uses and overlaying the ANHI (Agricultural Nitrate Hazard Index) Map. The integration of the above datasets has allowed to check the reliability of the previsional empirical model with respect to the hydrostratigraphic model based on a thorough stratigraphic model and to verify the real potential of contamination. 相似文献
10.
A. K. Verma R. K. Bajpai T. N. Singh P. K. Narayan Avi Dutt 《Arabian Journal of Geosciences》2011,4(7-8):1173-1188
Conceptual geological repositories are generally used for disposing spent nuclear wastes containing both high and low level of nuclear radiation and heat. Due to its long-lasting effect, it is imperative to analyze its long-term effect on the surrounding rock. Before analyzing radiation and thermal effect, it is important to have structurally stable cavern because designing an opening in rock is a more difficult problem than designing the structure made of steel. Underground rocks are under stress because of the weight of the overlying rock, and in addition, an underground opening will produce a stress concentration and stress relaxation in the surrounding rock. If the induced stress in the surrounding rock exceeds its strength, the opening will fail either by fracturing or by deforming more than the tolerable limit. In this paper, the stability of four different shapes of excavation has been examined for conceptual geological repositories in Indian context. This has been done using equivalent continuum numerical model which has been incorporated in the commercial finite difference code-FLAC-3D. Effects of opening shapes on stress distribution, subsidence of crown and side wall, and their stability have been analyzed and discussed. The validation of FLAC3D software for its applicability in conceptual underground geological repositories has been done with a published literature. 相似文献
11.
对于高边坡、大型地下洞室、深基坑等逐层开挖工程,开挖形象具有动态变化的特点,工程形象变化大、开挖持续时间长、开挖面位置不断变化,开挖面地质信息必须及时采集,而传统的静态三维影像建模方法难以满足要求。本文以典型的逐层开挖工程——乌东德水电站大坝建基面边坡为研究对象,探索出一套三维影像建模方法,通过无人机倾斜摄影结合像控点测量、数据处理、模型构建,获取建基面整体三维影像。影像成果质量优良,位移偏差一般为5.1~7.9 cm,精度满足一般工程需要。此三维影像建模方法为工程信息存储、分析、展示和后期应用奠定了基础,取得了良好效果。 相似文献
12.
正在设计施工的某大型水电站地下洞室群地质条件复杂,其开挖支护方案对围岩稳定性非常重要,因此,对支护方案进行优化研究非常必要。为更真实地模拟岩体的力学特性,研究施工过程中岩体的损伤破坏,根据不可逆热力学理论建立了弹塑性损伤模型和损伤演化方程,并编制了三维弹塑性损伤有限元程序D-FEM,具有模拟开挖与支护、计算速度快、群组功能等特点。建立大型地下洞室群三维数值模型,将通过实测地应力反演的应力作为初始地应力。采用D-FEM模拟了不同支护方案洞室群的施工过程,通过分析洞室围岩的应力、位移和破损区,支护方案2的支护效果最好,建议采用此方案。考虑岩体损伤演化后与FLAC3D塑性区相比,洞室群边墙中部的破损区显著增加,因此,程序可应用于地下工程的稳定性分析 相似文献
13.
随着城市的快速发展,地铁车站周边开发的建筑越来越多,周边建筑施工对地铁车站将产生不可避免的不利影响。本文结合某大型建筑深基坑工程的设计、施工及监测数据,通过有限元计算,分析基坑开挖施工力学特征,研究基坑施工对临近地铁车站的变形影响。研究发现,基坑采用合理的地下连续墙、钻孔灌注桩等围护体系、适当的被动区加固方式、科学的分基坑开挖施工组织等措施,可以保证基坑开挖施工对临近车站的影响在可控制、可接受的范围内,为软土地区类似基坑的设计、施工提供参考经验。 相似文献
14.
Porewater pressure increases in soil and rock from underground chemical and nuclear explosions 总被引：3，自引：0，他引：3
Wayne A. Charlie George E. Veyera Deanna S. Durnford Donald O. Doehring 《Engineering Geology》1996,43(4):225-236
A review and analysis of chemical and nuclear explosive-induced porewater pressure increases and induced rise in groundwater table elevations (groundwater mounding) is presented. Our analysis indicates that residual pore pressure increases and groundwater mounding can be induced by underground chemical and nuclear explosions to scaled distances of 879 m/(kt)1/3. This relationship is linear over seven orders of magnitude of explosive energy ranging from a 0.01 kg chemical explosion to a 100 kt nuclear explosion and is valid for a wide variety of saturated geological profiles. Underground chemical explosions, and probably underground nuclear explosions have the potential to induce liquefaction of water-saturated soils to scaled distances of about 260 m/(kt)1/3. 相似文献
15.
16.
地质力学模型试验是在复杂条件下进行大型地下洞室围岩稳定性分析的重要研究手段,能够真实地反映地质构造和工程结构的空间关系,准确模拟施工过程对厂房稳定性的影响以及岩体的破坏特征。双江口水电站地下洞群模型试验中采用预留孔径灌胶方式进行高精度的棒式光纤光栅（FBG）位移传感器的埋设,以便对洞室周边的位移进行量测,同时应用FLAC3D进行数值模拟比较。结果表明：棒式光纤光栅传感器量测方法解决了模型试验中内部变形小、量测精度要求高的问题,与数值模拟结果相吻合;试验中传感器埋设的方法是成功的,无论是开挖阶段还是超载阶段传感器均能有效地监测模型内部变形,揭示地下洞室群模型在开挖阶段和超载阶段的变形机制和破坏特征。 相似文献
17.
一种面向对象的三维地下空间矢量数据模型 总被引：1，自引：0，他引：1
针对地下空间的真三维连续特性以及建模过程的动态交互编辑与分析要求,提出了一种新的三维地下空间矢量数据模型。该模型采用面向对象思想对地下各种空间对象进行抽象描述;利用模型中的线段要素增强几何元素之间拓扑连接关系的维持,为地质体的切割和地下工程体的开挖等分析提供了算法上的便利;引入拓扑面更好地表达了地下空间对象之间的拓扑邻接关系。该模型在三维地下空间数据的存储管理、查询分析以及实时逼真绘制等方面都表现出较好的性能,适用于地下勘探工程的建模与分析。 相似文献
18.
地下空间是城市发展中土地资源综合利用的重要途径,准确掌握地下空间利用现状对城市地下地籍调查和权属认定意义重大。地下空间情况复杂,地球物理探测面临诸多现实难题。通常布置二维剖面只能对地下空间进行＂拼凑式＂成像,无法整体刻画地下空间。三维地震技术以全方位获取反射信号,能准确对目标对象予以成像,但目前尚无应用于城市地下地籍调查的实践。结合专题研究,以小块体、浅层采集等方法,以实现该技术在地下空间调查中的应用。通过具体实验,初步形成了实施技术方案,并对应用效果与存在问题进行了分析。 相似文献
19.
隐伏断裂的探测是城市地质调查的基本要素.成都中心城区位于成都平原东侧,整体表现为受断裂控制、西陡东缓的陆内逆冲断陷盆地,并以覆盖巨厚的第四纪砂卵石沉积为特征,隐伏断裂发育特征不明,识别难度大.本文基于多年来成都中心城区地铁勘察、房建地基勘察、水文地质调查、基坑探槽等累积的数据,结合实地勘察与其他地学数据整合信息库,运用计算机三维精细建模与可视化技术,建立了成都中心城区精细三维地质模型.结合实测钻孔剖面图,在精细刻画的三维基岩起伏面上识别出两条明显的北东向隐伏断裂,确定了其在中心城区经过的具体位置及展布形态;结合上覆砂卵石层的分布,确认蒲江-新津-成都断裂为主控断裂,早更新世开始活动,双桥子-包江桥断裂为其次级断裂,晚更新世初开始活动;同时发现了一条可能受断裂控制、贯穿市区的北西西向凹陷带.三维地质模型与沉积层等厚线图揭示了隐伏断裂对沉积的控制作用,砂卵石层沉降中心由西北向东南逐渐迁移.此次研究建立了成都中心城区的三维基岩起伏面模型,识别出了隐伏断裂具体位置及其主要特征,为城市地下空间合理利用、科学规划及地震危险性评价等提供了重要的基础资料. 相似文献
20.
M. Langer 《Engineering Geology》1993,34(3-4):159-167
The problem of waste disposal in Germany has been solved by using a combination of above-ground and underground disposal. Site selection criteria and precise criteria for the performance assessment of various types of waste disposal are available. In view of long-term safety of disposal, it is necessary to include geological and hydrogeological viewpoints in addition to purely engineering viewpoints.
In particular, the geotechnical site-specific safety assessment is described, as defined by the government in “Technical Regulations on Wastes” (TA-Abfall) in the section “Underground Disposal”. This safety assessment must cover the entire system comprising waste, cavern/mine and surrounding rock. For this purpose geo-mechanical models have to be developed.
According to the multi-barrier principle, the geological setting must be able to contribute significantly to isolation of the waste over longer periods. The assessment of the integrity of the geological barrier can only be performed by making calculations with validated geomechanical models.
Various engineering geological data are required for the selection of a site, for the design and construction of a repository, and for a safety analysis for the post-operational phase. These data can only be attained by the execution of a comprehensive site-specific geomechanical exploration and investigation program. The planning and design of an underground repository in rock salt layers are described, as an example for the various steps of this type of safety assessment. 相似文献