Análise da subsidencia xerada pola escavación de dous túneles utilizando máquinas tuneladoras EPB (Earth Pressure Balance). Estudio da relación entre as variables de perforación e os asentamentos inducidos.

Currently the development in the use of underground space in urban environments is being instrumental in the planning and management of cities. This use of underground space arises as a result of the growth of cities, demanding infrastructure that accommodate and respond to all that the city needs demand. One of the key pieces to carry out sustainable urban development is improving its transport and communication. For this, new rail and road networks are being designed and implemented using the latest technologies in underground excavations. An example of development of underground space for improving the transport network is the one that is running in London; Crossrail. Crossrail is the largest underground construction project that is currently underway in Europe. It is the development of a new railway network that would connect the West Zone (Reading) with the East (Abbey Wood and Shenfield) London area, through the British capital. A total of 42 km of tunnels have been excavated tunnel boring machines used. 10 sections of tunnels have been dug with 8 TBMs that have passed under the city, sharing space with the underground network in London, the Thames river, large Racacielos, old foundations, stations, collectors and underground rivers at depths up 40 m. This urban environment requires absolute control of the subsidence that may arise. The objective is to determine the influence that the excavation of two tunnels by EPB, has generated over the seats and set a proceeding that, depending on the evolution of the excavation, anticipate the possibility of generating a seat surface.Actualmente el desarrollo en el uso del espacio subterraneo en entornos urbanos esta siendo pieza clave en la planificacion y gestion de las ciudades. Este uso del espacio subterrano surge como la consecuencia del crecimiento de las ciudades, demandando infraestructuras que den cabida y respuesta a todas las necesidades que la ciudad demanda. Una de las piezas clave para poder llevar a cabo un desarrollo urbano sostenible es la mejora de su red de transporte y comunicacion. Para ello, nuevas redes ferroviarias y viarias se estan diseñando y ejecutando, utilizando las ultimas tecnologias en excavaciones subterraneas. Un ejemplo de desarrollo del espacio subterraneo para la mejora de la red de transporte es el que se esta ejecutando en Londres; Crossrail. Crossrail es el mayor proyecto de construccion subterraneo que se esta realizando actualmente en Europa. Consiste en el desarrollo de una nueva red ferroviaria que conectara la la zona Oeste (Reading) con la zona Este (Abbey Wood y Shenfield) de Londres, atravesando la capital britanica. Un total de 42 km de tuneles han sido excavados utilizado maquinas tuneladoras. 10 tramos de tuneles se han excavado con 8 tuneladoras que han pasado por debajo de la ciudad, compartiendo el espacio con la red de metro de Londres, el rio Thames, grandes racacielos, antiguas cimentaciones, estaciones, colectores y rios subterraneas a profundidades de hasta 40 m. Este entorno urbano exige un control absoluto de las subsidencias que se puedan generar. El objetivo es determinar la influencia que la excavacion de dos tuneles mediante EPB, tiene sobre los asientos generados y establecer un procedimento que, en funcion de la evolucion de la excavacion, anticipe la posibilidad de generar un asiento en superficie.Actualmente o desenvolvemento no uso do espazo subterráneo en ambientes urbanos está fundamental para a planificación e xestión das cidades. Este uso subterrano espazo xorde como resultado do crecemento das cidades, esixindo infraestrutura que acomodar e responder a todo o que a cidade ten demanda. Unha das pezas clave para levar a cabo o desenvolvemento urbano sostible e mellorar o seu transporte e comunicación. Para iso, novas redes ferroviarias e estradas están sendo deseñados e implementados utilizando as recentes tecnoloxías en escavacións subterráneas. Un exemplo de desenvolvemento do espazo subterráneo para mellorar a rede de transporte é o que está a ser executado en Londres; Crossrail. Crossrail é o maior proxecto de construción subterránea que está actualmente en curso en Europa. É o desenvolvemento dunha nova rede ferroviaria que ligaría a Zona Oeste (Reading) co Oriente (Abbey Wood e Shenfield) Área de Londres, a través da capital británica. Un total de 42 km de túneles foron excavados túnel máquinas de perforación usados. 10 seccións de túneles foron escavados con 8 TBM que pasaron baixo a cidade, dividindo espazo coa rede de metro de Londres, o río Támesis, gran Racacielos, fundacións antigas, estacións, recolectores e ríos subterráneos en profundidades de ata 40 m. Este ambiente urbano esixe control absoluto da subsidência que poida xurdir. O obxectivo é determinar a influencia que a escavación de túneles por dous EPB, xerou ao longo dos asentos e establecer un proceso que, dependendo da evolución da excavación, prevista a posibilidade de xerar unha superficie de asento

Tunnel Engineering

This volume presents a selection of chapters covering a wide range of tunneling engineering topics. The scope was to present reviews of established methods and new approaches in construction practice and in digital technology tools like building information modeling. The book is divided in four sections dealing with geological aspects of tunneling, analysis and design, new challenges in tunnel construction, and tunneling in the digital era. Topics from site investigation and rock mass failure mechanisms, analysis and design approaches, and innovations in tunnel construction through digital tools are covered in 10 chapters. The references provided will be useful for further reading

Behaviour of segmental tunnel lining under static and dynamic loads

The aim of the research thesis is to provide a three-dimensional numerical model suitable to interpret the static and dynamic behaviour of a kind of segmental tunnel lining in soft soil. The static performance of the structure is investigated during the tunnel construction, involving the main tunnelling loads, obtaining the evolution of the state of stress and strain in the lining. The dynamic performance of segmental lining has been investigated both under uniform and not uniform seismic loads. In the case of uniform seismic load, pseudo static and full dynamic approaches have been compared, while non-linear coupled analysis have been used to investigate the post-earthquake lining condition. A study of the seismic vulnerability of such structures has been conducted based on fragility curves for different levels of damage. A procedure for the forecast method of risk assessment has been proposed for the case of segmental tunnel lining assuming as critical damage parameter the longitudinal joints rotation. Furthermore, a study of feasibility of Earthquake Early Warning System, EEWS, based on thresholds has been conducted through a probabilistic and a real-time approach for such tunnel structure. The coupling effect of multi-directional seismic motion both in transversal and longitudinal direction of the tunnel has also taken into account in the evaluation of dynamic tunnel behaviour. A comparison between the effect of synchronous and not synchronous seismic motion along the tunnel axis has been done in terms of dynamic increment of the components of forces in the lining

Local use of rock materials – production and utilization State-of-the-art

During excavation of tunnels, large amounts of rock material are produced. This excavated rock material is utilized to a varying extent for road-, railway- and concrete purposes, but significant amounts are used as deposits on land, in fjords or lakes. For both economic and environmental reasons there is a great potential in increasing the utilization of excavated rock material locally in the same project or in neighboring projects. Initially, this report presents a brief introduction to the geology in Norway and some comparable European countries. This may give an indication which main rock type to expect in different areas during tunnelling. Further, the development within the main directions of tunnelling is discussed. Also, an overview of equipment and crushing technology is given. The boundaries of this report are excavated material used in asphalt, concrete, road construction and railway construction. For each area of utilization, a presentation of the currenttechnical requirements for various uses of the material in Norway is given. Examples of projects where excavated material is utilized are presented. Finally, possibilities and obstacles when it comes to utilizing excavated rock material are discussed, and further work is proposed.publishedVersio

Tunnelling

Tunnelling has become a fragmented process, excessively influenced by lawyers'notions of confrontational contractual bases. This prevents the pooling of skills, essential to the achievement of the promoters' objectives. Tunnelling: Management by Design seeks the reversal of this trend. After a brief historical treatment of selected developments, t

Experiments in tunnel-soil-structure interaction

Urbanisation will require significant expansion of underground infrastructure, which results in unavoidable ground displacements that affect the built environment. Predicting the interaction between a tunnel, the soil and existing structures remains an engineering challenge due to the highly non-linear behaviour of both the soil and the building. This thesis investigates the interaction between a surface structure and tunnelling-induced ground displacements. Specifically, novel three-dimensionally printed building models with brittle material behaviour, similar to masonry, were developed and tested in a geotechnical centrifuge. This enabled replication of building models with representative global stiffness values and realistic building features including strip footings, intermediate walls, a rough soil-structure interface, building layouts and façade openings. By varying building characteristics, the impact of structural features on both the soil and building response to tunnelling in dense sand was investigated. Results illustrate that the presence of surface structures considerably altered the tunnelling-induced soil response. The building-to-tunnel position notably influences the magnitude of soil displacements and causes localised phenomena such as embedment of building corners. An increase of the façade opening area and building length reduces the alteration of the theoretical greenfield settlements, in particular the trough width. Moreover, the impact of varying the building layout is discussed in detail. For several building-tunnel scenarios, building distortions are quantified and the crucial role of building features is demonstrated. Structures spanning the greenfield inflection point experienced more deformation than identical structures positioned in either sagging or hogging, and partitioning a structure either side of the greenfield inflection point is shown to lead to unconservative damage assessments. Results also quantify the significant extent to which structural distortions increase as façade openings and building length increases. Observed building damage and cracking patterns confirm the reported trends. The experimental results are used to evaluate the performance of available methods to assess the behaviour of buildings to tunnelling. Predictions ignoring soil-structure interaction are usually overly conservative, while approaches based on the relative stiffness of a structure and the soil result in inconsistent predictions, though some methods performed better than others. Practical improvements to consider structural details when assessing this tunnel-soil-structure system are finally proposed.Engineering and Physical Sciences Research Council (grant EP/KP018221/1), Crossrai

Advanced Underground Space Technology

The recent development of underground space technology makes underground space a potential and feasible solution to climate change, energy shortages, the growing population, and the demands on urban space. Advances in material science, information technology, and computer science incorporating traditional geotechnical engineering have been extensively applied to sustainable and resilient underground space applications. The aim of this Special Issue, entitled “Advanced Underground Space Technology”, is to gather original fundamental and applied research related to the design, construction, and maintenance of underground space

The Investigation Of Stability Of Tunnels And Settlements With Centrifuge Modelling

Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2012Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 2012Dünya üzerindeki şehirlerin gelişimi sürdürdükçe yaşanan yer problemleri yer altı sistemlerinin kullanımını zorunlu hale getirmektedir. Genellikle ulaşım problemlerine çözüm sağlayan tünellerin artık yaygın olarak kullanılmaya başlanmasına rağmen, büyük şehirlerde tünel inşaatı beraberinde önemli problemleride açığa çıkarmaktadır. Bilindiği gibi inşaat metodu ne olursa olsun, tünel açımı sırasında deformasyonların oluşumu kaçınılmazdır. Günümüzde birçok numerik analiz programı yardımıyla bilgisayar ortamında deformasyonlar rahatlıkla hesaplanabilmesine rağmen, zemin parametrelerinde küçük alanlarda oluşabilen büyük değişiklikler kesin deformasyonların bulunmasını engellemekte, yalnızca yaklaşık sonuçlar elde edilmesine olanak sağlanmaktadır. Bu durum büyük projelerde ve özellikle spt değeri elliden küçük olan zeminlerde, sığ tünellerin inşaatı sırasında belirsizlikler yaşanmasına neden olabilmektedir. Belirsizliklerin giderilebilmesi ise ancak gerçek bir modelleme ile mümkündür. Bu çalışmada, santrifüj modelleme yöntemi ile Spt değeri 50’den küçük olan zeminlerde tünel yüzeinde göçmenin engellenmesi için gerekli olan yüzey basıncı ve gerekli yüzey basıncının kaybı nedeni ile tünel hattı boyunca oluşan zemin deformasyonları farklı dane çapı dağılımlarına, farklı tabaka kalnlıklarına ve sürsarj yüküne bağlı olarak incelendi. Çalışma sonuçları ve literatür verileri karşılaştırıldı.In most of the larger cities underground transportation systems are preferred. Such systems are constructed in urban areas and involve a tunnel, especially in soft ground and in shallow zones. Underground structures are most well-known challenge for civil engineers in respect to planning of the measurements and performing of underground structure. One of major concerns for tunneling operations in urban area is the effect on neighbouring buildings, because the tunneling operation and near structures highly interact with each other. Whatever the used construction method is, the excavation of a tunnel causes displacement around the openning and may expand towards the ground surface. The dislocations of the buildings interact with the ground movement, and the rigidity of existing structures will promote reduction of the magnitude of displacements induced by tunnelling. In this investigation, to determine displacements, centrifuge modelling is used. The small scale centrifuge model, which is newly designed, provided dependable information about the face collapse of a shallow tunnel. A required support pressure for shield driven tunnels in soft materials, and the ground deformations along the longitudinal section of the tunnel model, can be identified by simulating a loss of tunnel face stability. In soft ground and shallow zones, formation of deformations which are taking place according to the different soil grain size, different line thickness and whether there is a structure on the surface or not is discussed in this investigation.Yüksek LisansM.Sc

Parallel computation in efficient non-linear finite element analysis with applications to soft-ground tunneling project

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2004.Includes bibliographical references.Reliable prediction and control of ground movements represent an essential component of underground construction projects in congested urban environments, to mitigate against possible damage to adjacent structures and utilities. This research was motivated by the construction of a large underground cavern for the Rio Piedras station in San Juan, Puerto Rico. This project involved the construction of a large, horseshoe-shaped cavern (17m wide and 16m high) in weathered alluvial soils. The crown of the cavern is located less than 5.5m below existing buildings in a busy commercial district. Structural support for the cavern was provided by a series of 15 stacked drifts. These 3m square-section galleries were excavated mainly by hand and in-filled with concrete, while a compensation grouting system was designed to mitigate effects of excavation-induced ground movements on the overlying structures. Unexpectedly large settlements occurred during drift construction and overwhelmed the grouting system that was intended to compensate for tunnel-induced movements. Although two dimensional, non-linear finite element analyses of the stacked- drift construction suggest that movements exceeding 100mm can be expected, the 2-D representation of excavation and ground support is overly simplistic and represents a major source of uncertainty in these analyses. Massive computational efforts make more comprehensive 3-D models of the construction sequence completely impractical using existing finite element software with direct or iterative solver methods.(cont.) This thesis develops, implements, and applies an efficient parallel computation scheme for solving such large-scale, non-linear finite element analyses. The analyses couple a non- overlapping Domain Decomposition technique known as the FETI algorithm (Farhat & Roux, 1991) with a Newton-Raphson iteration scheme for non-linear material behavior. This method uses direct factorization of the equilibrium equations for sub-domains, while solving a separate interface problem iteratively with a mechanically consistent, Dirichlet pre- conditioner. The implementation allows independence of the number of sub-domains from the number of processors. This provides flexibility on mesh decomposition, control between iterative interface solutions and direct sub-domain solutions, and load balance in shared heterogeneous clusters. The analyses are performed with the developed code, FETI- FEM (programmed in C++ and MPI) using syntax consistent with pre-existing ABAQUS software. Benchmark testing on a Beowulf cluster of 16 interconnected commodity PC computers found excellent parallel efficiency, while the computation time scales with the number of finite elements, NE, according to a power law with exponent, p = 1.217. Parallel 3-D FE analyses have been applied in modeling the drift excavation, primary lining and infilling for the stacked-drift construction assuming a simplified soil profile. The resulting FE model comprised approximately 30,000 20-noded quadratic displacement-based elements, representing almost 400,000 degrees of freedom (at least one order of magnitude larger than any prior model reported in the geotechnical literature) and was sub-divided into 168 sub-domains ...by Yo-Ming Hsieh.Ph.D

Geotechnical Engineering for the Preservation of Monuments and Historic Sites III

The conservation of monuments and historic sites is one of the most challenging problems facing modern civilization. It involves, in inextricable patterns, factors belonging to different fields (cultural, humanistic, social, technical, economical, administrative) and the requirements of safety and use appear to be (or often are) in conflict with the respect of the integrity of the monuments. The complexity of the topic is such that a shared framework of reference is still lacking among art historians, architects, structural and geotechnical engineers. The complexity of the subject is such that a shared frame of reference is still lacking among art historians, architects, architectural and geotechnical engineers. And while there are exemplary cases of an integral approach to each building element with its static and architectural function, as a material witness to the culture and construction techniques of the original historical period, there are still examples of uncritical reliance on modern technology leading to the substitution from earlier structures to new ones, preserving only the iconic look of the original monument. Geotechnical Engineering for the Preservation of Monuments and Historic Sites III collects the contributions to the eponymous 3rd International ISSMGE TC301 Symposium (Naples, Italy, 22-24 June 2022). The papers cover a wide range of topics, which include: 　 - Principles of conservation, maintenance strategies, case histories - The knowledge: investigations and monitoring - Seismic risk, site effects, soil structure interaction - Effects of urban development and tunnelling on built heritage - Preservation of diffuse heritage: soil instability, subsidence, environmental damages The present volume aims at geotechnical engineers and academics involved in the preservation of monuments and historic sites worldwide