scholarly journals Ground Deformation Characteristics Induced by Mechanized Shield Twin Tunnelling along Curved Alignments

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Dangzhong Wu ◽  
Kaiping Xu ◽  
Panpan Guo ◽  
Gang Lei ◽  
Kang Cheng ◽  
...  
Keyword(s):  
Ground Deformation ◽  
Three Dimensional ◽  
Ground Surface ◽  
Small Radius ◽  
Radius Of Curvature ◽  
Deformation Characteristics ◽  
Ground Deformations ◽  
Ground Surface Settlement ◽  
Tunnel Alignment ◽  
3D Finite Element Method

This paper investigates the ground deformation characteristics induced by mechanized shield twin tunnelling along curved alignments by adopting the nonlinear three-dimensional (3D) finite element method (FEM). The performance of the adopted FEM is demonstrated to be satisfactory by comparing the numerical analysis results with the field monitoring data in a typical case history and with the predicted results generated by a modified version of the Peck’s empirical Gaussian formula. It has been found that the tunnelling-induced transverse ground surface settlement troughs and the distributions of the subsurface horizontal and vertical ground displacements are mostly similar in both form and magnitude for the considered various radii of curvature of tunnel alignment including 50 m, 100 m, 150 m, 200 m, 250 m, 300 m, 400 m, and infinity (i.e., straight-line tunnel). Considering the variational characteristics of the ground deformations with the magnitude of the radius of curvature, the radius of curvature of 100 m can be regarded as a critical tunnel alignment radius of curvature controlling the transformation of the curved tunnelling-induced ground deformational behaviors. For the benefit of geotechnical engineers interested in curved tunnelling with a small radius of curvature, a discussion of the technologies for reducing the overexcavation and improving the accuracy of tunnel lining segment installation is also presented.

scholarly journals Deformation Characteristics of Raising, Widening of Old Roadway on Soft Soil Foundation

Symmetry ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2117
Author(s):  
Keke Li ◽  
Wenyuan Xu ◽  
Liang Yang
Keyword(s):  
Lateral Displacement ◽  
Soft Soil ◽  
Ground Surface ◽  
Surface Settlement ◽  
Deformation Characteristics ◽  
Construction Methods ◽  
Ground Surface Settlement ◽  
Total Settlement ◽  
Soil Foundation ◽  
Soft Soil Foundation

The deformation characteristics of a raised and widened old Chinese roadway on a soft soil foundation are investigated in this study via finite element numerical simulation. The rules of ground surface settlement, slope foot lateral displacement, and ground surface settlement evolution of the roadbed under three modes (one-time construction of an eight-lane expressway, widened four-lane expressway, and raised/widened four-lane expressway) are compared. The ground surface settlement process of the eight-lane road foundation, which is formed by first widening and then raising the road, is highly complex. The ground surface settlement curve under the old road foundation increases and then decreases. The lateral displacement of the slope foot also interacts with the widening and raising of the eight-lane roadbed foundation. The range of lateral displacement is 70.05, 42.58, 124.81, 104.54 mm. Fifteen years after construction, the total settlement of the raised and widened roadbed is much larger than that of the one built directly. The total settlement values at the center of the two roadbeds are 297.05 and 234.85 mm, respectively. This manuscript provides data support for the reconstruction and expansion of roads on soft soil foundations, for choosing appropriate construction methods to build roads, and for avoiding major road damage, which is of great significance to the construction of road infrastructure in the future.

Chapter 17 Mining-induced fault reactivation in the UK

2020 ◽  
Vol 29 (1) ◽  
pp. 425-432 ◽  
Author(s):  
Laurance Donnelly
Keyword(s):  
Coal Mining ◽  
Ground Deformation ◽  
Ground Surface ◽  
Surface Mining ◽  
Fault Reactivation ◽  
Mining Subsidence ◽  
Ground Movements ◽  
Ground Deformations ◽  
Coal Mining Subsidence ◽  
The Uk

AbstractFaults are susceptible to reactivation during coal mining subsidence. The effects may be the generation of a scarp along the ground surface that may or may not be accompanied by associated ground deformation including fissuring or compression. Reactivated faults vary considerably in their occurrence, height, length and geometry. Some reactivated faults may not be recognizable along the ground surface, known only to those who have measured the ground movements or who are familiar with the associated subtle ground deformations. In comparison, other reactivated faults generate scarps up to several metres high and many kilometres long, often accompanied by widespread fissuring of the ground surface. Mining subsidence-induced reactivated faults have caused damage to roads, structures and land. The objective of this chapter is to provide a general overview of the occurrence and characteristics of fault reactivation in the UK.

Analysis of buried pipelines subjected to ground surface settlement and heave

2015 ◽  
Vol 52 (8) ◽  
pp. 1058-1071 ◽  
Author(s):  
George P. Kouretzis ◽  
Dimitrios K. Karamitros ◽  
Scott W. Sloan
Keyword(s):  
Three Dimensional ◽  
Ground Surface ◽  
Ease Of Use ◽  
Surface Settlement ◽  
Buried Pipelines ◽  
Analytical Methodology ◽  
Ground Surface Settlement ◽  
Potential Alternative ◽  
Internal Forces ◽  
Pipeline Design

This paper presents an analytical methodology for the calculation of internal forces and strains developing in continuous buried pipelines that cross geotechnically problematic areas and are susceptible to permanent ground surface settlement or heave. Material nonlinearity effects are introduced in the solution via an iterative procedure, while taking into account the effect of pipeline elongation on its response. The use of a versatile bilinear expression to describe the stress–strain response of the pipeline material renders the method appropriate for steel, high-density polyethylene (HDPE), concrete, and cast iron pipelines alike. Comparison of the analytical results against those from benchmark finite element analyses highlights the effectiveness of the simplified analysis. The method is a potential alternative to elaborate three-dimensional nonlinear numerical analyses that are often used in pipeline design practice, and offers ease-of-use with no expense in accuracy, at least for problems involving simple pipeline geometries.

scholarly journals Deformation information system for facilitating studies of mining-ground deformations, development, and applications

2014 ◽  
Vol 14 (7) ◽  
pp. 1677-1689 ◽  
Author(s):  
J. Blachowski ◽  
W. Milczarek ◽  
P. Stefaniak
Keyword(s):  
Data Mining ◽  
Information System ◽  
Spatial Data ◽  
Ground Deformation ◽  
Data Extraction ◽  
Three Dimensional ◽  
Horizontal Displacement ◽  
Spatial Data Mining ◽  
Calculation Of Parameters ◽  
Ground Deformations

Abstract. The paper presents the concept of the deformation information system (DIS) to support and facilitate studies of mining-ground deformations. The proposed modular structure of the system includes data collection and data visualisation components, as well as spatial data mining, modelling and classification modules. In addition, the system integrates interactive three-dimensional models of the mines and local geology. The system is used to calculate various parameters characterising ground deformation in space and time, i.e. vertical and horizontal displacement fields, deformation parameters (tilt, curvature, and horizontal strain) and input spatial variables for spatial data classifications. The core of the system in the form of an integrated spatial and attributive database has been described. The development stages and the functionality of the particular components have been presented and example analyses utilising the spatial data mining and modelling functions have been shown. These include, among other things, continuous vertical and horizontal displacement field interpolations, calculation of parameters characterising mining-ground deformations, mining-ground category classifications, data extraction procedures and data preparation preprocessing procedures for analyses in external applications. The DIS has been developed for the Walbrzych coal mines area in SW Poland where long-time mining activity ended at the end of the 20th century and surface monitoring is necessary to study the present-day condition of the former mining grounds.

scholarly journals Multi-Sensor InSAR Assessment of Ground Deformations around Lake Mead and Its Relation to Water Level Changes

2021 ◽  
Vol 13 (3) ◽  
pp. 406
Author(s):  
Mehdi Darvishi ◽  
Georgia Destouni ◽  
Saeid Aminjafari ◽  
Fernando Jaramillo
Keyword(s):  
Water Level ◽  
Surface Deformation ◽  
Ground Deformation ◽  
Water Storage ◽  
Negative Relationship ◽  
Ground Surface ◽  
Subsurface Water ◽  
Lake Mead ◽  
Ground Deformations ◽  
Water Level Changes

Changes in subsurface water resources might alter the surrounding ground by generating subsidence or uplift, depending on geological and hydrogeological site characteristics. Improved understanding of the relationships between surface water storage and ground deformation is important for design and maintenance of hydraulic facilities and ground stability. Here, we construct one of the longest series of Interferometric Synthetic Aperture Radar (InSAR) to date, over twenty-five years, to study the relationships between water level changes and ground surface deformation in the surroundings of Lake Mead, United States, and at the site of the Hoover Dam. We use the Small Baseline Subset (SBAS) and Permanent scatterer interferometry (PSI) techniques over 177 SAR data, encompassing different SAR sensors including ERS1/2, Envisat, ALOS (PALSAR), and Sentinel-1(S1). We perform a cross-sensor examination of the relationship between water level changes and ground displacement. We found a negative relationship between water level change and ground deformation around the reservoir that was consistent across all sensors. The negative relationship was evident from the long-term changes in water level and deformation occurring from 1995 to 2014, and also from the intra-annual oscillations of the later period, 2014 to 2019, both around the reservoir and at the dam. These results suggest an elastic response of the ground surface to changes in water storage in the reservoir, both at the dam site and around the reservoir. Our study illustrates how InSAR-derived ground deformations can be consistent in time across sensors, showing the potential of detecting longer time-series of ground deformation.

scholarly journals Coseismic Ground Deformation Reproduced through Numerical Modeling: A Parameter Sensitivity Analysis

Geosciences ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 370 ◽  
Author(s):  
Panara ◽  
Toscani ◽  
Cooke ◽  
Seno ◽  
Perotti
Keyword(s):  
Stress Drop ◽  
Surface Deformation ◽  
Slip Surface ◽  
Ground Deformation ◽  
Numerical Models ◽  
Three Dimensional ◽  
Ground Surface ◽  
Line Of Sight ◽  
Coseismic Slip ◽  
2009 L’Aquila Earthquake

Coseismic ground displacements detected through remote sensing surveys are often used to invert the coseismic slip distribution on geologically reliable fault planes. We analyze a well-known case study (2009 L’Aquila earthquake) to investigate how three-dimensional (3D) slip configuration affects coseismic ground surface deformation. Different coseismic slip surface configurations reconstructed using aftershocks distribution and coseismic cracks, were tested using 3D boundary element method numerical models. The models include two with slip patches that reach the surface and three models of blind normal-slip surfaces with different configurations of slip along shallowly-dipping secondary faults. We test the sensitivity of surface deformation to variations in stress drop and rock stiffness. We compare numerical models’ results with line of sight (LOS) surface deformation detected from differential SAR (Synthetic Aperture Radar) interferometry (DInSAR). The variations in fault configuration, rock stiffness and stress drop associated with the earthquake considerably impact the pattern of surface subsidence. In particular, the models with a coseismic slip patch that does not reach the surface have a better match to the line of sight coseismic surface deformation, as well as better match to the aftershock pattern, than models with rupture that reaches the surface. The coseismic slip along shallowly dipping secondary faults seems to provide a minor contribution toward surface deformation.

Numerical Analysis of Composite Soil Nailing Wall

2014 ◽  
Vol 1065-1069 ◽  
pp. 48-52
Author(s):  
Shu Long Zhang ◽  
Fen Ting Lu
Keyword(s):  
Three Dimensional ◽  
Ground Surface ◽  
Horizontal Displacement ◽  
Soil Nailing ◽  
Construction Process ◽  
Three Dimensional Model ◽  
Foundation Pit ◽  
Finite Element Software ◽  
Ground Surface Settlement ◽  
Composite Soil Nailing

Abstract. The horizontal displacement of soil in slope and the change law of ground surface settlement are dynamically analyzed by building three dimensional-model of foundation pit with the finite element software, ABAQUS, to simulate the construction process of excavation and support, to figure out the influence of micro pile and waterproof curtain on composite soil nailing wall. The study indicates that mechanical model of soil nailing, waterproof curtain, micro pile, pre-stressed anchor interacting with soil can better simulate the construction process of composite soil nailing wall support and have higher calculation accuracy. The calculation can provide a reference for the design and construction of composite soil nailing wall.

scholarly journals Three-Dimensional Ground Settlement Induced by Metro Tunnel Excavation Considering the Influence of Group Piles

2016 ◽  
Vol 2016 ◽  
pp. 1-13
Author(s):  
Zou Jin-feng ◽  
Zhang Yan-jun ◽  
Dan Han-cheng
Keyword(s):  
Three Dimensional ◽  
Ground Surface ◽  
Soil Mass ◽  
Surface Settlement ◽  
Stochastic Medium ◽  
Ground Surface Settlement ◽  
Shear Displacement Method ◽  
Metro Tunnel ◽  
Group Piles ◽  
Prediction Approach

Considering the influence of group piles, a prediction model for three-dimensional ground surface settlement induced by circular metro tunnels excavation in incompressible rock masses is proposed based on the stochastic medium theory and the shear displacement method. The surface settlement caused by the metro tunnel opening is divided into two parts. One part is soil mass settlement caused by the metro tunnel opening and calculated by the stochastic medium theory. The other part is the settlement induced by the friction force between the group piles and the soil mass around the metro tunnel cross section and calculated by the shear displacement method. The three-dimensional prediction of the ground surface settlement is obtained by the linear superposition of the two parts. The validation of the proposed prediction approach is proved by comparing with the measured data and the numerical model of the double tunnels under thePuyuanoverpass where metro tunnels undercrossed group piles. The effects of buried depth, radial convergences, center distance of double tunnels, position and size of piles, and group piles are analyzed and discussed. The improved prediction approach can be applied to calculate the three-dimensional ground settlement, especially for the metro tunnels crossing through group piles.

scholarly journals Deformation information system for facilitating studies of mining ground deformations – development and applications

2013 ◽  
Vol 1 (5) ◽  
pp. 4801-4831
Author(s):  
J. B. Blachowski ◽  
W. Milczarek ◽  
P. Stefaniak
Keyword(s):  
Data Mining ◽  
Information System ◽  
Spatial Data ◽  
Ground Deformation ◽  
Data Extraction ◽  
Three Dimensional ◽  
Horizontal Displacement ◽  
Spatial Data Mining ◽  
Displacement Fields ◽  
Ground Deformations

Abstract. The paper presents the concept of the Deformation Information System (DIS) to support and facilitate studies of mining ground deformations. The proposed modular structure of the system includes data collection and data visualisation components, as well as spatial data mining, modelling and classification modules. In addition, the system integrates interactive three-dimensional models of the mines and local geology. The system is used to calculate various parameters characterising ground deformation in space and time, i.e. vertical and horizontal displacement fields, deformation parameters (tilt, curvature and horizontal strain) and input spatial variables for spatial data classifications. The core of the system in the form of an integrated spatial and attributive database has been described. The development stages and the functionality of the particular components have been presented and example analyses utilising the spatial data mining and modelling functions have been shown. These include, among other things, continuous vertical and horizontal displacement fields interpolations, calculation of parameters characterising mining ground deformations, mining ground category classifications, data extraction procedures and data preparation, pre-processing procedures for analyses in external applications. The DIS has been developed for the Walbrzych Coal Mines area in SW Poland where long-time mining activity has finished at the end of the 20th Century and surface monitoring is necessary to study present day condition of the former mining grounds.

Sign in / Sign up

Export Citation Format

Share Document