scholarly journals ANALYTICAL STUDY ON THE INFLUENCE OF DISTANCE OF THE PRIMARY INVERT CLOSURE FROM TUNNEL FACE ON GROUND SURFACE SETTLEMENT AND ITS APPLICATIONS

2008 ◽  
Vol 64 (3) ◽  
pp. 227-236
Author(s):  
Yasutaka MORISAKI ◽  
Yoshio MITARASHI ◽  
Yujing JIANG
Keyword(s):  
Analytical Study ◽  
Ground Surface ◽  
Surface Settlement ◽  
Tunnel Face ◽  
Ground Surface Settlement

scholarly journals Characteristics of Stress Transfer and Progressive Fracture in Overlying Strata due to Mining-Induced Disturbances

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Xiang-feng Lv ◽  
Hong-yuan Zhou ◽  
Ai-wen Wang ◽  
Chun Feng ◽  
Xiao-chun Xiao
Keyword(s):  
Numerical Simulation ◽  
Underground Mining ◽  
Ground Surface ◽  
Stress Transfer ◽  
Surface Settlement ◽  
Stress Concentrations ◽  
Tunnel Face ◽  
Working Face ◽  
Ground Surface Settlement ◽  
Overlying Strata

In this study, based on the mining of the 13210 working face in the Yima coal mine of the Gengcun village, China, a simplified mechanical model for the analysis of dynamic destabilization of the overlying strata during underground mining was constructed. The numerical simulation was used to analyze the stress patterns in the advanced abutments of the tunnel face and the characteristics of dynamic failures in the overlying strata. Furthermore, similitude experiments were conducted to study the process of stress release and deformation in the overlying strata, and to analyze the effects of overburden destabilization on the ground surface settlement. The theoretical analysis indicated that if the geometric parameters of a working face are fully determined, a stiffness ratio no greater than 1 is required for dynamic destabilization to occur. The numerical simulation results show that the stress in the overlying strata decreases with a decrease in distance from the tunnel face. The stresses in the advanced abutments initially increase with an increase in distance from the tunnel face, followed by a decrease in stress, and an eventual stabilization of the stress levels; this corresponds to the existence of a “stress build-up zone,” “stress reduction zone,” and “native rock stress zone.” In similitude experiments, it was observed that a “pseudoplastic beam” state arises after the local stresses of the overlying strata have been completely released, and the “trapezoidal” fractures begin to form at stress concentrations. If the excavation of the working face continues to progress, the area of collapse expands upward, thereby increasing the areas of the fracture and densification zones. Owing to the nonuniform settlement of the overlying strata and the continuous development of bed-separating cracks, secondary fractures will be generated on both sides of the working face, which increase the severity of the ground surface settlement.

Analysis of Surface Subsidence Rule of the Shallow Subway Tunnel Construction

2013 ◽  
Vol 671-674 ◽  
pp. 1081-1086 ◽  
Author(s):  
Fei Fei Wang ◽  
Hui Ren Bai ◽  
Jing Jing Li
Keyword(s):  
Ground Surface ◽  
Calculation Model ◽  
Surface Subsidence ◽  
Surface Settlement ◽  
Tunnel Construction ◽  
Maximum Point ◽  
Subway Tunnel ◽  
Monitoring Frequency ◽  
Ground Surface Settlement ◽  
Value Range

In order to study the Dalian Metro section 202(Cujin Road station-Chunguang Street station, which is shallowly buried and covered with plain fill)’s ground surface settlement, the monitoring measuring station was built during the construction. After 3 months’ measuring by precision level,the data shows that the maximum point is in the center line of the tunnel of the upper part. The settlement is about 25.66-31.82mm. This paper put forward the concept of the distance span ratio β, β effective value range was - 4 <β< 4,Surface subsidence is closely related with β, Severe surface subsidence stage is -2 <β< 2, Occupy whole deformation is 67.5-77.6%,settlement rate about 0.84-0.93mm/d, so should strengthen the monitoring frequency, Suggest increases site tour. Field test results and the ground surface settlement calculation model winkle are identical with each other; the monitoring results have important guiding significance and reference for Dalian subway and the similar shallow depth excavation tunnel construction.

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.

scholarly journals Analysis of the Additional Stress and Ground Settlement Induced by the Construction of Double-O-Tube Shield Tunnels in Sandy Soils

2019 ◽  
Vol 9 (7) ◽  
pp. 1399 ◽  
Author(s):  
Wen Zhao ◽  
Peng-jiao Jia ◽  
Lin Zhu ◽  
Cheng Cheng ◽  
Jianyong Han ◽  
...  
Keyword(s):  
Ground Surface ◽  
Field Measurements ◽  
Surface Settlement ◽  
Additional Stress ◽  
Underground Construction ◽  
Shield Tunneling ◽  
Engineering Project ◽  
Ground Surface Settlement ◽  
Potential Damage ◽  
Lateral Friction

Double-O-tube shield tunneling has attracted increasing attention because it offers cost-efficiency in underground construction. Prediction of ground surface settlement and the variety of additional stresses induced by shield construction is crucial to underground construction in metropolises since excessive settlement could trigger potential damage to the surrounding environment. The additional stresses induced by the propulsion of double-O-tube shields are calculated by means of the Mindlin’s equations of elasticity. The characteristics of additional stresses are analyzed with compound Gauss-Legendre integral arithmetic, and the frontal additional thrust, the lateral friction, and the ground loss are taken into account. Subsequently, based on field measurements, the maximum settlement coefficient and width of the settlement trough coefficient of the typical Peck formula are modified. The predictive curve of the Peck formula is closer to the engineering measured data than that of the typical formula. The cut-off functions of ground surface settlement caused by double-O-tube tunnel shield construction are proposed and can predict the shape of ground surface settlement, such as single peak or double peak. The correctness of the proposed functions is verified based on an engineering project.

Surface settlement during shield tunnelling at CH218 in Taipei

1998 ◽  
Vol 35 (1) ◽  
pp. 159-168 ◽  
Author(s):  
Chang-Yu Ou ◽  
Richard N Hwang ◽  
Wei-Jung Lai
Keyword(s):  
Ground Surface ◽  
Earth Pressure ◽  
Surface Settlement ◽  
Pressure Balance ◽  
Transit System ◽  
Ground Surface Settlement ◽  
Earth Pressure Balance Shield ◽  
Shield Tunnelling ◽  
Earth Pressure Balance ◽  
Twin Tunnels

This paper presents the surface settlement performance induced by the foamed type of earth pressure balance shield in contract CH218 of the Hsintien Line of the Taipei Rapid Transit System. The surface settlement characteristics caused by the single tunnel and by twin tunnels with reference to two sections spaced at 87 m are studied. Field observations indicate that the surface settlement trough due to the single tunnel can be represented by the normal distribution. The distance of the inflection point to the tunnel center and maximum surface settlement value are consistent with those found in the literature. The characteristics of the surface settlement trough are related to the type of the soil, particularly where the crown of the tunnel is located in a layered soil deposit. The ground surface settlement induced by twin tunnels was found to be larger than estimated using the principle of superposition.Key words: shield tunnelling, surface settlement, field observation.

Prediction of Shield Tunnelling-Induced Ground Settlement Considering Soil-Water Coupled and around Soil Disturbance Damage

2010 ◽  
Vol 168-170 ◽  
pp. 357-364
Author(s):  
Ji Feng Liu ◽  
Bo Liu ◽  
Hui Zhi Zhang
Keyword(s):  
Numerical Simulation ◽  
Soil Water ◽  
Ground Surface ◽  
Soil Disturbance ◽  
Surface Settlement ◽  
Shield Tunnel ◽  
Tunnel Construction ◽  
Ground Settlement ◽  
Ground Surface Settlement ◽  
Shield Tunnelling

to evaluate the influence of soil-water coupled and shield tunnel construction induced around soil disturbance damage on ground surface settlement, the process of shield tunnel construction induced around soil disturbance is analyzed, the FLAC3D numerical simulation are carried out, and a newly-modified tunnelling-induced ground settlement calculation method based on disturbance degree of around soil and soil-water coupled is presented, and these methods are applied in case of Beijing Metro 10thLine. It is indicated that considering the influence of the shield tunnelling-induced around soil disturbance damage, and soil-water coupled induced soil properties weakening and the excess pore water pressure dissipating induced soil consolidation to the ground surface settlement are necessary, the calculating result of the newly-modified surface settlement prediction method, and the result FLAC3D numerical simulation all agree well with in-site observed data of Beijing Metro 10th Line.

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.

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