scholarly journals Surface Settlement Analysis of Double-Line Shield Passing Through a Power Tunnel and Directly Cutting Pile Foundation

2021 ◽  
Vol 861 (5) ◽  
pp. 052092
Author(s):  
Jianhua Zhang ◽  
Hongwei Wang ◽  
Peixin Chen ◽  
Feng Xu ◽  
Jun Wu
Keyword(s):  
Pile Foundation ◽  
Surface Settlement ◽  
Double Line ◽  
Settlement Analysis

scholarly journals Efficiency Analysis of Foundation System

Neutron ◽  
2022 ◽  
Vol 21 (2) ◽  
pp. 60-73
Author(s):  
Resi Aseanto ◽  
Ali Ramdani Bagaskara ◽  
Syafwandi ◽  
Agung Sumarno
Keyword(s):  
Bearing Capacity ◽  
Pile Foundation ◽  
Efficiency Analysis ◽  
Combined System ◽  
Foundation Design ◽  
Cost Overruns ◽  
Land Prices ◽  
Raft Foundation ◽  
Long Time ◽  
Settlement Analysis

The increasing number of residents in South Tangerang has an impact on increasing the need for lower housing. The development of vertical housing with the market name of flats, apartments and is the most effective anticipatory solution to overcome land prices which result in market limitations, especially for the upper middle class. This 32-storey apartment project uses a combined foundation system between drill pile foundation & raft foundation. With the combination of these two very massive systems, of course, it will have a very expensive cost to implement and take a long time to complete. In order to avoid cost overruns, the foundation design must look at the possibilities. To determine the efficiency of the combined system foundation design between pile bored foundation & raft foundation, the researchers analyzed the value of the bearing capacity and also the settlement that occurred in the existing foundation using the Poulos method, the equivalent Raft method and the Vesic method. From the results of the study, it was found that the contribution of the pile foundation bearing capacity was 24.10%. the placement of the raft foundation is 75.90% and the settlement analysis using the Poulos 8.95cm method, the 12.41cm Equivalent Raft method and the Vesic 12.1cm method, these three results are close to the maximum settlement limit.

scholarly journals Numerical Study on the Disturbance Effect of Short-Distance Parallel Shield Tunnelling Undercrossing Existing Tunnels

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Zhen Huang ◽  
Chenlong Zhang ◽  
Helin Fu ◽  
Huangshi Deng ◽  
Shaokun Ma ◽  
...  
Keyword(s):  
Numerical Model ◽  
Short Distance ◽  
Maximum Stress ◽  
Numerical Study ◽  
Soil Layer ◽  
Field Monitoring ◽  
Surface Settlement ◽  
Shield Tunnel ◽  
Double Line ◽  
Shield Tunnelling

The construction of new tunnels poses a threat to the operational safety of closely existing tunnels, and the construction mode of parallel undercrossing over short distances has the most significant impact. In this study, a new double-line shield tunnel parallel undercrossing of existing tunnels in Hefei, China, is taken as an example. A three-dimensional (3D) numerical model using FLAC3D finite difference software was established. The dynamic construction of the new double-line shield tunnel undercrossing the existing subway tunnel over a short distance and in parallel was simulated. The pattern of existing tunnel settlement and change in lining stress caused by the shield tunnelling process were analyzed. The reliability of simulation was verified through field-monitoring data. Finally, based on the numerical model, the effects of change in stratum sensitivity on the settlement of existing tunnel, lining internal force, and surface settlement are discussed. The results show that during shield tunnelling, the maximum ground settlement is 3.9 mm, the maximum settlement at the arch waist of existing tunnel near the new tunnel is 7.75 mm, and the maximum vault settlement is 5.38 mm. The maximum stress of lining of existing tunnel before the excavation is 7.798 × 105 Pa. After the construction of double-line shield tunnel, the maximum stress of lining is 1.124 × 106 Pa, an increase of 44% than that before the construction. The surface settlement and tunnel settlement are sensitive to the weakening of soil layer strength, and lining stress is not affected by the weakening of soil layer strength. The field-monitoring results are consistent with the numerical simulation results, and the model calculation is reliable. This study plays an important role in ensuring construction safety and optimizing the construction risk control of a tunnel.

scholarly journals Surface Settlement Analysis Induced by Shield Tunneling Construction in the Loess Region

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Caihui Zhu
Keyword(s):  
Sensitivity Analysis ◽  
Influencing Factors ◽  
Water Levels ◽  
Surface Settlement ◽  
Soil Consolidation ◽  
Shield Tunneling ◽  
Construction Period ◽  
Maximum Surface Settlement ◽  
Loess Region ◽  
Settlement Analysis

The influence and prediction of shield tunneling construction on surface settlement (SS) and adjacent buildings is a hot topic in underground space engineering. In this work, several analytical methods are utilized to estimate the maximum surface settlement (MSS) and conduct a parametric sensitivity analysis based on Xi’an Metro line 2. The results show that there are mainly nine factors influencing the SS induced by shield tunneling construction in loess strata. The disturbance degree of the surrounding soil during the shield advancing stage has the largest influence on the SS, followed by the seepage of the shield lining segments or falling water levels, which lead to the overlying soil consolidation. After this is the grouting filling effect at the shield tail, followed by the reinforcement effect of the tunnel foundation and the track. The smallest influencing factors on the SS are the shield overexcavation and improper shield attitudes during the construction period. The sensitivity analysis results of the above influencing factors may offer a scientific guidance for the control of shield tunneling construction.

scholarly journals Effects of Different Construction Sequences on Ground Surface Settlement and Displacement of Single Long Pile due to Twin Paralleled Shield Tunneling

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Kan Huang ◽  
Yiwei Sun ◽  
Xianqiang Huang ◽  
Yujian Li ◽  
Meng Jiang ◽  
...  
Keyword(s):  
Urban Areas ◽  
Pile Foundation ◽  
Ground Surface ◽  
Horizontal Displacement ◽  
Element Model ◽  
Surface Settlement ◽  
Pile Foundations ◽  
Shield Tunneling ◽  
Construction Sequence ◽  
Ground Surface Settlement

Shield tunneling activities inevitably pass through pile foundations at close distance in densely urban areas. Various studies have investigated the interaction between newly constructed tunnels and existing pile foundations. However, the influence of different construction sequences of twin paralleled shield tunneling on single long pile is seldom considered. A case was found in the project of Changsha Metro Line 5, where the twin paralleled tunnels were constructed near the Wanjiali Viaduct piles. A three-dimensional finite element model was established to analyze the pier settlement, ground surface settlement trough, and the vertical and horizontal displacement of pile under different construction sequences in layered soil. The results show that the adjacent pile and surrounding environment are affected substantially with the change of construction sequence of twin paralleled tunnels. The construction sequence of condition (b), in which the tunnel closer to the pile foundation is first constructed and then the tunnel farther away from the pile foundation is second constructed, can reduce the settlement of pier by 13.1%, the maximum surface settlement by 7.0%, the maximum vertical displacement of pile foundation by 7.9%, and the maximum horizontal displacement by 6.9%. The present findings can provide reference for similar projects.

Analisis Daya Dukung Tanah Dan Bahan Pondasi Tiang Pancang Pada Pembangunan Jembatan Kab. Jombang

2020 ◽  
Vol 9 (1) ◽  
pp. 32-37
Author(s):  
Ruslan Hidayat ◽  
Saiful Arfaah
Keyword(s):  
Carrying Capacity ◽  
Pile Foundation ◽  
Heavy Traffic ◽  
Traffic Volume ◽  
Material Strength ◽  
Cone Penetrometer ◽  
The Village

One of the most important factors in the structure of the pile foundation in the construction of the bridge is the carrying capacity of the soil so as not to collapse. Construction of a bridge in the village of Klitik in Jombang Regency to be built due to heavy traffic volume. The foundation plan to be used is a pile foundation with a diameter of 50 cm, the problem is what is the value of carrying capacity of soil and material. The equipment used is the Dutch Cone Penetrometer with a capacity of 2.50 tons with an Adhesion Jacket Cone. The detailed specifications of this sondir are as follows: Area conus 10 cm², piston area 10 cm², coat area 100 cm², as for the results obtained The carrying capacity of the soil is 60.00 tons for a diameter of 30 cm, 81,667 tons for a diameter of 35 cm, 106,667 tons for a diameter of 40 cm, 150,000 tons for a diameter of 50 cm for material strength of 54,00 tons for a diameter of 30 cm, 73,500 tons for a diameter of 35 cm, 96,00 tons for a diameter of 40 cm, 166,666 tons for a diameter of 50 cm

Effect of Geocell Reinforcement above Buried Pipes on Surface Settlement

2018 ◽  
Vol 9 (2) ◽  
pp. 86 ◽  
Author(s):  
Mohammed Yousif Fattah ◽  
Waqed Hameed Hassan ◽  
Sajjad E. Rasheed
Keyword(s):  
Surface Settlement ◽  
Buried Pipes ◽  
Geocell Reinforcement
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