Assessment of the ground subsidence and lining forces due to tunnel advancement

Download
2009
Karamanlı, Ömer
The use of sprayed concrete lining is common in tunneling practice since it allows the application of non-circular tunnel sections and complex tunnel intersections. Low capital cost of construction equipment is also an important factor for the selection of the sprayed concrete lining. In general the use of sprayed concrete lining is referred as New Austrian Tunneling Method (NATM). Depending on the requirements regarding tunnel heading stability and limitations on tunneling induced soil displacements, tunnel cross sections often advanced by different construction sequences and round lengths in NATM. For the purpose of assessing the effects of excavation sequence, round length, soil stiffness and tunnel depth on surface settlements and on tunnel lining forces, a parametric study has been carried out, considering short-term and long-term soil response. Three dimensional finite element analysis are performed to model the excavation sequence and stress distribution around the tunnel lining during excavation. The parameters used in the parametric study can be listed as: tunnel diameter, tunnel depth, round length and soil stiffness. Existing analytical and empirical solutions, which are used for prediction of ground subsidence due to tunneling and forces on tunnel lining, are also reviewed in this study; and their predictions are compared with the results obtained from numerical analysis. This comparison also provides an opportunity to evaluate the performance of the existing efforts. The variations between the results obtained from different methods are discussed and it is concluded that the limitations of the existing methods are the primary reason of the variations between results.

Suggestions

Structural fire safety of standart circular railroad tunnels under different soil conditions
Böncü, Altan; Caner, Alp; Department of Civil Engineering (2008)
In many tunnel designs, reinforced concrete tunnel lining design is selected based on construction requirements rather than design loads. A constant cross-section is typically used along a tunnel even if the design loads change from one location to another, especially for tunnels constructed by tunnel boring machines (TBM). Factor of safety against failure is not constant along the length of tunnel and is typically high at shallow depth regions. Factor of safety during a rare event is usually much less than...
A comparative assessment of an existing reinforced concrete building by using different seismic rehabilitation codes and procedures
Öztürk, İsmail; Sucuoğlu, Haluk; Department of Civil Engineering (2006)
Lateral load carrying capacities of reinforced concrete structures which are designed by considering only gravity loads or according to outdated earthquake codes can be insufficient. The most important problem for these buildings is the limited ductility of the frame elements. How to evaluate the performance of an existing structure and to what level to strengthen it had been major concerns for structural engineers. Recent earthquakes which occurred in the Marmara Region in the last decade have increased th...
Dynamic effects of moving traffic on railway bridges
Cinek, Fatih; Yılmaz, Çetin; Department of Civil Engineering (2010)
In this study, dynamic effects on high speed railway bridges under moving traffic are investigated. Within this context, the clear definition of the possible dynamic effects is provided and the related studies that exist in literature are investigated. In the light of those studies, analytical procedures that are defined to find the critical dynamic responses such as deflections, accelerations and resonance conditions are examined and a MatLab programming language is written to obtain the responses for diff...
Analysis of mechanical behavior of high performance cement based composite slabs under impact loading
Satıoğlu, Azize Ceren; Gülkan, Polat; Department of Civil Engineering (2009)
Studies on the behavior of steel fiber reinforced concrete (SFRC) and slurry infiltrated fibrous concrete (SIFCON) to impact loading have started in recent years. Using these relatively new materials, higher values of tensile and compressive strength can be obtained with greater fracture toughness and energy absorption capacity, and therefore they carry a considerable importance in the design of protective structures. In this thesis, computational analyses concerning impact loading effect on concrete, steel...
Behavior of curved steel trapezoidal box-girders during construction
Topkaya, Cem; Frank, KH (Elsevier BV, 2004-05-01)
In recent years, steel, trapezoidal box-girders for curved highway interchanges have been used extensively. For these structural systems, the majority of the steel girder cross-sectional stresses occur during the concrete pouring sequence. This paper describes a comprehensive study on the behavior of curved girders during construction. Data collected for the current research shows significant differences between the measured and predicted quantities, particularly for later pours. An overview of the steel-co...
Citation Formats
Ö. Karamanlı, “Assessment of the ground subsidence and lining forces due to tunnel advancement,” M.S. - Master of Science, Middle East Technical University, 2009.