scholarly journals Assessment on Segment Joint to Improve Soil-Tunnel Interaction

2018 ◽  
Vol 250 ◽  
pp. 01005
Author(s):  
Siti Norafida Jusoh ◽  
Hisham Mohamad ◽  
Aminaton Marto ◽  
Fauziah Kassim
Keyword(s):  
Nonlinear Model ◽  
Field Data ◽  
Ground Deformation ◽  
Ground Surface ◽  
Bending Moment ◽  
Settlement Pattern ◽  
Tunnel Lining ◽  
Tunnel Construction ◽  
Joint Modelling ◽  
Tunnel Model

The bending moment of tunnel lining can be influenced by non-uniform ground pressures and joint eccentricities. Influence of joint interaction that induces flexural moment behaviour in segmental tunnel lining was investigated for the project Circle Line Stage 3 (C852), Serangoon Interchange Station. By considering behaviour of segment joint (which can affects the tunnel circumferential and longitudinal safety in overall), the tunnel lining behaviour and displacement of the ground surrounding the tunnel were evaluated. The segment joint modelling in simplified dual-jointed model and in fully soil-tunnel model were developed to assess the effect of segment joint on the overall tunnel response. Ground deformation or settlement trough at the ground surface resulted from the effect of tunnel construction and interaction between soil, tunnel, segment joints and ring joints was predicted. Results showed that with different use of segment joints give different longitudinal settlement. Hinge-nonlinear model together with separated rings model lead to the highest resemblance of surface settlement pattern to the field data when compare to tie model.

Numerical Simulation on the Stress and Strain of Lining Structure with Double Shield Tunneling Construction

2012 ◽  
Vol 605-607 ◽  
pp. 2425-2429
Author(s):  
Feng Wang ◽  
Tie Jun Cui
Keyword(s):  
Ground Surface ◽  
Calculation Model ◽  
Tunnel Lining ◽  
Concrete Lining ◽  
Shield Tunnel ◽  
Tunnel Construction ◽  
Three Dimension ◽  
Shield Tunneling ◽  
Deformation Law ◽  
Lining Structure

This paper takes the Section 201 of shield construction engineering in Dalian Metro Line 2 as an example to analyze the deformation law of surrounding soil and the tunnel lining structure stress during shield tunnel construction. The shield tunnel construction is simulated dynamically by ADINA and the shield tunnel structure model of the concrete lining is established. This model is a three-dimension nonlinear finite element calculation model concerned with the grouting soil and original state soil. Taking the soil lithology in the upper layer and interact influences, we analyzed the dynamic process of shield construction, soil grouting and lining supporting and the stress distribution in difference reinforced concrete supporting segments and the ground settlement characteristics. Through numerical analysis method to study the deformation law of soil surrounding tunnel and the stress in tunnel lining, we get the results to compare with the results of Peck formula under the same condition. After generating the conclusions, we can provide several suggestions for shield tunneling construction, lining segment design and control of the ground surface settlement during the construction.

Calculation and Analysis of the Construction Program in Nanjing Rail Transit Line 1 from South Yanande's Door to NingDan Road

2012 ◽  
Vol 256-259 ◽  
pp. 1447-1452
Author(s):  
Ying Chun Fu
Keyword(s):  
Ground Surface ◽  
Bending Moment ◽  
Surface Settlement ◽  
Tunnel Construction ◽  
Rail Transit ◽  
Construction Process ◽  
Finite Element Software ◽  
Ground Surface Settlement ◽  
Subway Construction ◽  
Supporting Force

It is the key to success or failure of the construction that we control the ground surface settlement, vault sink and supporting force by the choice of the reasonable construction method in the subway construction process. Based on the project profiles of the tunnel in Nanjing orbit traffic line 1 from South Yan'an road to NingDan road, the article mainly carries on the numerical simulation to construction program by using ANSYS finite element software according to the joint arch tunnel construction of the double and triple arch in the entry end .The article mainly has an analysis from the ground surface settlement, the strata, axial force of supporting structure, bending moment and other aspects. The results show that the program is feasible. The article provids guidance to the future construction of similar projects .

scholarly journals Effect of Tunnel Progress on the Settlement of Existing Piled Foundation

2019 ◽  
Vol 41 (2) ◽  
pp. 102-113 ◽  
Author(s):  
Raid Ramzi Al-Omari ◽  
Madhat Shakir Al-Soud ◽  
Osamah Ibrahim Al-Zuhairi
Keyword(s):  
Ground Deformation ◽  
Three Dimensional ◽  
Ground Surface ◽  
Tunnel Boring Machine ◽  
Longitudinal Direction ◽  
Tunnel Lining ◽  
Elastic Model ◽  
Element Analysis ◽  
Tunnel Boring ◽  
Three Dimensional Finite Element

AbstractTunnel construction below or adjacent to piles will affect the performance and eventually the stability of piles due to ground deformation resulting in the movement of piles and changes in the axial force distribution along the piles. A three dimensional finite element analysis using PLAXIS 3D (2013) was performed to study the behaviour of a single pile and 3 x 3 piles group during the advancement of shield tunnelling in ground. The 10-node tetrahedral elements were used to model both the soil and the tunnel lining. The Hardening Soil (HS) model was used to simulate the soil structure interaction at the tunnel-soil interface. An isotropic elastic model was used for the pile, piles cap, tunnel lining and tunnel boring machine shield (TBM). Several parametric studies were attempted including the longitudinal, lateral, and vertical tunnel location relative to pile embedded in different types of soil (clay or sand). The results showed that the pile head settlement increases during the tunnelling advancement in larger values than that for ground surface settlement. A zone of influence was determined in the range of twice the tunnel diameter in the longitudinal direction (forward and backward of the pile), and transverse direction (left and right of the tunnel centreline). If the tunnel boring is kept off this zone then there is no fear of pile collapse.

scholarly journals Behavior Characteristics of Single Batter Pile under Vertical Load

2021 ◽  
Vol 11 (10) ◽  
pp. 4432
Author(s):  
Jiseong Kim ◽  
Seong-Kyu Yun ◽  
Minsu Kang ◽  
Gichun Kang
Keyword(s):  
Bearing Capacity ◽  
Relative Density ◽  
Model Test ◽  
Ground Surface ◽  
Bending Moment ◽  
Vertical Position ◽  
Vertical Load ◽  
Behavior Characteristics

The purpose of this study is to grasp the behavior characteristics of a single batter pile under vertical load by performing a model test. The changes in the resistance of the pile, the bending moment, etc. by the slope of the pile and the relative density of the ground were analyzed. According to the results of the test, when the relative density of the ground was medium and high, the bearing capacity kept increasing when the angle of the pile moved from a vertical position to 20°, and then decreased gradually after 20°. The bending moment of the pile increased as the relative density of the ground and the batter angle of the pile increased. The position of the maximum bending moment came closer to the ground surface as the batter angle of the pile further increased, and it occurred at a point of 5.2~6.7 times the diameter of the pile from the ground surface.

scholarly journals Changes in ground deformation prior to and following a large urban landslide in La Paz, Bolivia revealed by advanced InSAR

2018 ◽  
Author(s):  
Nicholas J. Roberts ◽  
Bernhard T. Rabus ◽  
John J. Clague ◽  
Reginald L. Hermanns ◽  
Marco-Antonio Guzmán ◽  
...  
Keyword(s):  
Ground Deformation ◽  
Ground Surface ◽  
Slope Instability ◽  
Small Scale ◽  
Spatial And Temporal Patterns ◽  
La Paz ◽  
Fine Grained ◽  
Measured Displacement ◽  
Optical Satellite Images ◽  
Displacement Patterns

Abstract. We characterize and compare creep preceding and following the 2011 Pampahasi landslide (∼ 40 Mm3 ± 50 %) in the city of La Paz, Bolivia, using spaceborne RADAR interferometry (InSAR) that combines displacement records from both distributed and point scatterers. The failure remobilised deposits of an ancient landslide in weakly cemented, predominantly fine-grained sediments and affected ∼ 1.5 km2 of suburban development. During the 30 months preceding failure, about half of the toe area was creeping at 3–8 cm/a and localized parts of the scarp area showed displacements of up to 14 cm/a. Changes in deformation in the 10 months following the landslide are contrary to the common assumption that stress released during a discrete failure increases stability. During that period, most of the landslide toe and areas near the headscarp accelerated, respectively, to 4–14 and 14 cm/a. The extent of deformation increased to cover most, or probably all, of the 2011 landslide as well as adjacent parts of the slope and plateau above. The InSAR-measured displacement patterns – supplemented by field observations and by optical satellite images – indicate that kinematically complex, steady-state creep along pre-existing sliding surfaces temporarily accelerated in response to heavy rainfall, after which the slope quickly achieved a slightly faster and expanded steadily creeping state. This case study demonstrates that high-quality ground-surface motion fields derived using spaceborne InSAR can help to characterize creep mechanisms, quantify spatial and temporal patterns of slope activity, and identify isolated small-scale instabilities. Characterizing slope instability before, during, and after the 2011 Pampahasi landslide is particularly important for understanding landslide hazard in La Paz, half of which is underlain by similar, large paleolandslides.

Detecting land deformation due to groundwater changes with InSAR observations - the case of the island of Gotland, Sweden

2021 ◽  
Author(s):  
Mehdi Darvishi ◽  
Fernando Jaramillo
Keyword(s):  
Land Subsidence ◽  
Groundwater Level ◽  
Ground Deformation ◽  
Soil Depth ◽  
Ground Surface ◽  
Groundwater Depletion ◽  
Groundwater Levels ◽  
Small Baseline Subset ◽  
Small Baseline ◽  
The Baltic

<p>In the recent years, southern Sweden has experienced drought conditions during the summer with potential risks of groundwater shortages. One of the main physical effects of groundwater depletion is land subsidence, a geohazard that potentially damages urban infrastructure, natural resources and can generate casualties. We here investigate land subsidence induced by groundwater depletion and/or seasonal variations in Gotland, an agricultural island in the Baltic Sea experiencing recent hydrological droughts in the summer. Taking advantage of the multiple monitoring groundwater wells active on the island, we explore the existence of a relationship between groundwater fluctuations and ground deformation, as obtained from Interferometric Synthetic Aperture Radar (InSAR). The aim in the long-term is to develop a high-accuracy map of land subsidence with an appropriate temporal and spatial resolution to understand groundwater changes in the area are recognize hydroclimatic and anthropogenic drivers of change.</p><p>We processed Sentinel-1 (S1) data, covering the time span of 2016-2019, by using the Small BAseline Subset (SBAS) to process 119 S1-A/B data (descending mode). The groundwater level of Nineteen wells distributed over the Gotland island were used to assess the relationship between groundwater depletion and the detected InSAR displacement. In addition to that, the roles of other geological key factors such as soil depth, ground capacity in bed rock, karstification, structure of bedrock and soil type in occurring land subsidence also investigated. The findings showed that the groundwater level in thirteen wells with soil depths of less than 5 meters correlated well with InSAR displacements. The closeness of bedrock to ground surface (small soil depth) was responsible for high coherence values near the wells, and enabled the detection land subsidence. The results demonstrated that InSAR could use as an effective monitoring system for groundwater management and can assist in predicting or estimating low groundwater levels during summer conditions.</p>

scholarly journals Experimental observation on laterally loaded pile in unsaturated silty soil

2019 ◽  
Vol 56 (11) ◽  
pp. 1545-1556 ◽  
Author(s):  
L.M. Lalicata ◽  
A. Desideri ◽  
F. Casini ◽  
L. Thorel
Keyword(s):  
Water Table ◽  
Ground Surface ◽  
Bending Moment ◽  
Data Interpretation ◽  
Partial Saturation ◽  
Laterally Loaded Piles ◽  
Silty Soil ◽  
Centrifuge Tests ◽  
Surface Data ◽  
Laterally Loaded

An experimental study was carried out to investigate the effects of soil partial saturation on the behaviour of laterally loaded piles. The proposed study was conducted by means of centrifuge tests at 100g, where a single vertical pile was subjected to a combination of static horizontal load and bending moment. The study was conducted on a silty soil characterized with laboratory testing under saturated and unsaturated conditions. During flight, two different positions of water table were explored. The influence of density was investigated by compacting the sample with two different void ratios. Finally, the effects of a variation of saturation degree on the pile response under loading were studied by raising the water table to the ground surface. Data interpretation allows drawing different considerations on the effects of partial saturation on the behaviour of laterally loaded piles. As expected, compared to saturated soils, partial saturation always leads to a stiffer and resistant response of the system. However, the depth of the maximum bending moment is related to the position of the water table and the bounding effects induced by partial saturation appear to be more important for loose soils.

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.

3D Visual Technology of Geo-Deformation Disasters Induced by Mining Subsidence Based on ArcGIS Engine

2012 ◽  
Vol 500 ◽  
pp. 428-436 ◽  
Author(s):  
Ke Ming Yang ◽  
Jun Ting Ma ◽  
Bo Pang ◽  
Yi Bin Wang ◽  
Ran Wang ◽  
...  
Keyword(s):  
Coal Mining ◽  
Surface Deformation ◽  
Ground Deformation ◽  
Ground Surface ◽  
Horizontal Displacement ◽  
Mining Subsidence ◽  
Underground Coal Mining ◽  
Vertical Movements ◽  
Probability Integral Method ◽  
Arcgis Engine

Mining subsidence often produces significant horizontal and vertical movements at the ground surface, the surface deformation induced by underground coal mining can be predicted by probability integral method, and the surface geo-deformation disasters can be visualized based on GIS components. A three dimensional (3D) visualizing system of surface geo-deformation information is designed and developed with ArcGIS Engine and C# in the study. According to the surface deformation-predicted data induced by underground coal mining in Guobei Coalmine of Huaibei mine field, the extents and degrees of ground deformation disasters are visualized in 3D views for surface vertical subsidence, slope, curvature, horizontal displacement and horizontal strain based on the GIS-developed application platform.

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