Safety Assessment on Retaining and Protecting of Deep Foundation Excavation Adjacent to the Existing Railway

2013 ◽  
Vol 361-363 ◽  
pp. 1511-1514
Author(s):  
Wen Jing Si ◽  
Yu Jie Wang ◽  
Ying Fu Gao ◽  
Hui Zhou
Keyword(s):  
Horizontal Displacement ◽  
Surface Settlement ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Overturning Stability ◽  
Neighboring Structure ◽  
Deep Foundation Excavation ◽  
Set Up ◽  
The Stability ◽  
Stability Checking

Mizhuo highway overpass crosses Jingha railway. Deep foundation excavation can cause the neighboring structure safety factor drops. To ensure the stability of the Jingha railway embankment, retaining and protecting of deep foundation excavation was set up around the foundation pit. The incremental calculation method was used to analyze the stress deformation of retaining pile and surface settlement near the deep foundation pit. The overall stability checking and anti-overturning stability checking of deep foundation excavation meet the specification requirements. The maximum horizontal displacement of retaining pile is 6.0 mm and 6.6 mm respectively. Surface settlement can not impact the existing railway embankment. In construction practice the retaining pile can be able to effectively ensure the safety of the neighboring structure and to reduce the probability of accidents.

scholarly journals Displacement Monitoring during the Excavation and Support of Deep Foundation Pit in Complex Environment

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Zhouqiang Li
Keyword(s):  
Axial Force ◽  
Time History ◽  
Horizontal Displacement ◽  
Underground Water ◽  
Surface Settlement ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit ◽  
Anchor Cable ◽  
The North

Taking a super large deep foundation pit project as an example, the horizontal displacement of crown beam and driveway, surface settlement, axial force of anchor cable, and underground water level in the construction process of the foundation pit are dynamically monitored and analyzed. The excavation deformation rule of the deep foundation pit and the influence of excavation on surrounding buildings are analyzed. The results show that, with the excavation of the foundation pit, the crown beam and driveway of the foundation pit incline towards the direction of the pit and eventually tend to be stable. The variation of axial force of the prestressed anchor cable in the first layer of the foundation pit is basically consistent with the variation of horizontal displacement time history. The variation trend of the groundwater level at each side of the foundation pit is different but tends to be stable in a short time. In the whole monitoring period, the cumulative settlement value of each area of the foundation pit is within the controllable range, but the surface settlement of the north side of the foundation pit and a surrounding building has not reached stability, so it is suggested to extend the monitoring time of settlement in the relevant area.

Manufacturing and Hoisting Technology for Reinforcement Cage of Deep Foundation Excavation Bored Piles

2014 ◽  
Vol 1044-1045 ◽  
pp. 633-637 ◽  
Author(s):  
Xin Zhou ◽  
Guang Xiu Fang ◽  
Ping Zhang ◽  
Yuan Qing Leng
Keyword(s):  
Steel Reinforcement ◽  
Detailed Calculation ◽  
Construction Technology ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Element Analysis ◽  
Bored Pile ◽  
Steel Processing ◽  
Deep Foundation Excavation ◽  
Set Up

Combined with the Beijing Business Center (CBD) core district Z14 plots commercial finance project (hereinafter referred to as the "CBD project") foundation pit construction, introduces the deep foundation pit of bored pile reinforcement cage fabrication and erection construction technology. In the construction process, through the site set up a special steel processing and production platform, the localization of the flange and other measures to solve the steel reinforcement cage positioning and connection construction difficulties. Combining the engineering fact, detailed calculation process of lifting steel cage hanging position, lifting machinery and hoisting rigging selection, and through the ANSYS software of finite element analysis and put forward specific measures to ensure the quality of steel reinforcement cage.

System Stability of Bored Piles with Steel Supports for Deep Foundation Pits in Sandy Pebble Stratum

2020 ◽  
Vol 14 ◽  
Author(s):  
Xuansheng Cheng ◽  
Junliang Hong ◽  
Qingchun Xia ◽  
Haibo Liu ◽  
Fei Gao ◽  
...  
Keyword(s):  
Stability Analysis ◽  
System Stability ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit ◽  
Analysis Theory ◽  
Overall Stability ◽  
Overturning Stability ◽  
Bored Piles ◽  
The Stability

Background: At present, there is few researches on the stability of the supporting structure of bored piles with steel supports for deep foundation pits, and it is even less common to use this support method for deep foundation pits in sandy pebble stratum. This paper studied the stability of the deep foundation pit support of the Southwest Jiaotong University Station in Chengdu, China, using the stability analysis theory of bored piles with steel supports for deep foundation pits Objective: The study aims to show the stability of steel supports for deep foundation pits Methods: The overall stability, anti-overturning stability and uplift stability of the foundation pit are important components of the stability analysis of bored piles with steel supports for deep foundation pits. Aiming at the designed method and parameters of the bored piles with steel support for the deep foundation pit, an in-depth theoretical analysis and calculation of the overall stability, anti-overturning stability and uplift stability of the deep foundation pit is conducted respectively Results: The results show that the stability of the deep foundation pit using bored piles with steel support meets the requirements, meaning the design of this support form is safe and reasonable, thus ensuring the smooth progress of the project. Conclusion: The stability analysis of deep foundation pits in sandy pebble stratum provides ideas for the optimization of deep foundation pits and a reference for the stability analysis of deep foundation pits in sandy pebble stratum and other types of stratum.

Finite Element Analysis and Investigation of Double-Row Piles Supporting Structure

2013 ◽  
Vol 838-841 ◽  
pp. 779-785
Author(s):  
Liang Gu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Distribution ◽  
Maximum Shear Stress ◽  
Horizontal Displacement ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Double Row ◽  
Element Analysis ◽  
Supporting Structure

The double-row piles supporting structure is a new type of supporting and protecting for deep foundation excavation. It is widely used to in design of deep foundation pit. Now how to simply and effectively design the structure of double-row piles is in a research and discuss stage. Using the Midas GTS finite element method, the displacement and stress distribution of double-row piles in the different stages of excavation are obtained, and the horizontal displacement and stress distribution of double-row piles in the different stages of excavation are calculated. The results of Midas GTS finite element analysis as follows: (1) after the excavation of foundation pit, the horizontal displacement of pile-top is maximum. The horizontal displacement decreases gradually with depth increases. And the displacement of front row piles is larger than that of back row piles; (2) the maximum shear stress is at the distance 5m to the foundation basement. The higher bending moment at the pile-top and the distance 10m to the foundation basement are consistent with the actual monitoring date. (3) the results of finite element analysis is close to the Richard software and actual monitoring data. It is show that using the finite element analysis to analyze the double-row piles supporting structure with is veritable and credible.

Weight Analysis of Accident Factors in Deep Foundation Excavation Based on Analytic Hierarchy Process

2014 ◽  
Vol 711 ◽  
pp. 529-534
Author(s):  
Zi Sheng Yang ◽  
Jun Xia Liu ◽  
Yi Ren Wang
Keyword(s):  
Analytic Hierarchy Process ◽  
Deep Foundation ◽  
Accident Rate ◽  
Foundation Pit ◽  
Analytic Hierarchy ◽  
Weight Analysis ◽  
Deep Foundation Excavation ◽  
Hierarchy Process ◽  
Factor Set ◽  
Design Construction

For the past few years, great development has been achieved in deep foundation excavation. However, due to foundation excavation’s locality, individual diversity, complexity and uncertainty, the probability of accidents in foundation pit engineering tends to be greater than that in main works, and the accident rate may even reach about 20%, which makes the study on factors leading to foundation excavation accidents quite necessary and meaningful. By use of Analytic Hierarchy Process (AHP), this paper has figured out the ratio (weight) of the investigation, design, construction and other factors leading to foundation excavation accidents to the whole factor set, which is of great guiding significance to the study on prevention and treatment of foundation excavation accidents in future.

Control of Artificial Recharge on Foundation Pit Deformation due to Dewatering

2012 ◽  
Vol 594-597 ◽  
pp. 1901-1904
Author(s):  
Hua Yuan ◽  
Yan Hong
Keyword(s):  
Artificial Recharge ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deformation Control ◽  
Adjacent Building ◽  
The Difference ◽  
Prevention Method ◽  
Deep Foundation Excavation ◽  
Controlling Measures ◽  
Control Principle

In this paper, the currently available, feasible controlling measures for the deformation of foundation excavation and its surrounding environment are summarized systemically, which is mainly embodied in pit collapse, adjacent building differential settlement as well as underground pipeline cracking. Then first from the two aspects: artificial recharge used as prevention method and management measure separately, the paper illustrates the control principle, operation method and matters needing attention during artificial recharge. In addition, the difference between pumping well and recharge well are discusses. The research results will provide direction for the deformation control of deep foundation excavation and the operation of artificial recharge.

Research of Controlling for Pile-Anchor Joint Supporting Structure on Deformation of Deep Foundation Pits

2011 ◽  
Vol 261-263 ◽  
pp. 1809-1813
Author(s):  
Jin Biao Chen ◽  
Qiang Hu ◽  
Yuan Wu Zhou
Keyword(s):  
Soil Properties ◽  
Deformation Mechanism ◽  
Geotechnical Engineering ◽  
Reliability Theory ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit ◽  
Supporting Structure ◽  
Foundation Deformation ◽  
The Stability

The excavation of deep foundation pit is very complex in the field of geotechnical engineering, how to control the deformation of deep foundation pit and protect the environment is of great significance. This paper analyzed the deformation mechanism of pile-anchor joint supporting structure in detail, established a model for deformation controlling based on the reliability theory, and then analyzed the sensitivities of prestressed, pile stiffness, spacing and soil properties to foundation deformation. Combined with an engineering example, this paper verifies the stability and effectiveness of the model for deformation controlling. This study will provide some reference to similar projects.

scholarly journals Numerical Analysis on the Performance of the Underwater Excavation

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Bo Li ◽  
Cangqin Jia ◽  
Guihe Wang ◽  
Jun Ren ◽  
Gaofeng Lu ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Retaining Wall ◽  
Lateral Wall ◽  
Surface Settlement ◽  
Design Parameters ◽  
Analysis Model ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Wall Deflection ◽  
Total Settlement

Based on the Yongdingmen Station of Beijing Metro, the underwater excavation method for deep foundation pit was introduced. This study constructed a numerical analysis model to analyze the performance of surface settlement and lateral wall deflection in the process of underwater excavation. Results showed that this method was better to control the surface settlement and lateral wall deflection compared with other dewatering excavations. In detail, most of the surface settlement was caused during the dry excavation stage and dewatering excavation stage while the deflection caused by underwater excavation only accounted for about 10% of the total settlement. Besides, the maximum settlement occurred 0.25∼0.5 H e behind the retaining wall and the value was 0.04% H e . Similar to the result of the surface settlement, most of the lateral wall deflection had been completed before the underwater excavation, which only caused about 7% of the total deflection. The maximum wall deflection and its location were approximately 0.06% H e and 0.5 H e , respectively. Moreover, a series of 3D numerical analyses were studied on the design parameters of the underwater excavation method. This study can be used as a reference for general performance and structural design of foundation pits with underwater excavation.

Monitoring and Analysis on the Supporting Structure for Deep Foundation Pit

2014 ◽  
Vol 580-583 ◽  
pp. 787-790
Author(s):  
Hai Xia Sun ◽  
Ke Zhang ◽  
Si Li Chen
Keyword(s):  
In Situ Monitoring ◽  
Monitoring Data ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Metro Station ◽  
Deep Foundation Pit ◽  
Supporting Structure ◽  
Deformation Features ◽  
The Stability

This article mainly expounds the importance of in-situ monitoring on the construction process of deep foundation pit. Taking the deep foundation pit of some Shenyang metro station for example, the deformation features of the supporting structure and the internal and external of foundation pit is analyzed, according to the monitoring data of the fender pile displacement during the excavation of deep foundation pit. The conclusion is obtained that the timely and accurate in-situ monitoring information is necessary to guaranteeing construction safety. We should pay more attention to the excavation speed and exert the interior support timely during the excavation of foundation pit to avoid large deformation and danger. The analytical results of monitoring data shows that the whole stage of foundation pit excavation is stable and the fender pile with internal supports can guarantee the stability of foundation pit.

Research on Deformation Law of Deep Excavation Supporting Structures in Beijing Metro Station

2011 ◽  
Vol 243-249 ◽  
pp. 2338-2344
Author(s):  
Qing Yuan Li ◽  
Yang Wang
Keyword(s):  
Horizontal Displacement ◽  
Internal Force ◽  
In Situ Monitoring ◽  
Deep Excavation ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Metro Station ◽  
Deep Foundation Pit ◽  
Deformation Law

Taking deep excavation engineering in North Region of Senlin Park Station of Beijing Olympic Subway branch as engineering background, deformation law of enclosure structure of deep excavation are studied by the in-situ monitoring means .It shows that the maximum horizontal displacement of retaining pile is closely related with excavation depth and time. When the deep foundation pit is excavated to a certain depth, and steel brace hasn’t been erected, horizontal displacement of the pile tops is maximum. The location of the maximum horizontal displacement shifts down with foundation pit excavation and steel brace erection. With steel brace application, steel axis force decrease, so steel brace can effectively control horizontal displacements of retaining pile and internal force of steel in the pile. In addition, temperature has a certain effect to axis force of steel brace.

Sign in / Sign up

Export Citation Format

Share Document