Protection of prestressed high strength concrete pipe pile from large-scale excavation of deep foundation pit

Author(s):  
Zhong Chongmei
2020 ◽  
Vol 980 ◽  
pp. 282-290
Author(s):  
Shi Meng Wang ◽  
Xin Sheng Yin

Prestressed concrete pipe pile with high bearing capacity, the advantages of convenient construction, low cost and widely used in practical engineering, because of the prestressed high strength concrete in use process is in complex stress state, both are under a lot of vertical load, and horizontal seismic action needs to be considered at the same time, it is necessary under the condition of considering the vertical load bearing capacity of prestressed high strength concrete level and considering the loading level, the horizontal bearing capacity. Scholars at home and abroad based on the simple hypothesis, puts forward the calculation method of a lot of interaction with soil, in the future will be adopted in calculation, using ABAQUS finite element analysis, this paper established the three-dimensional finite element model of prestressed concrete pipe pile, respectively under different vertical pressure (P = 4000 kn, P = 4800 kn, P = 6000 kn) one-way load and calculated the horizontal bearing capacity, and under repeated load, respectively to study the size of the different vertical pressure and different reinforcement stirrup ratio on its bearing capacity and seismic performance. The results show that the stiffness of pipe pile decreases significantly with the increase of vertical pressure under different vertical loads. With the increase of vertical load, the ductility and energy dissipation capacity of the components decrease gradually. The horizontal bearing capacity of prestressed high strength concrete pipe decreases with the increase of vertical pressure. However, its amplitude decreases with the increase of vertical pressure value.


2012 ◽  
Vol 193-194 ◽  
pp. 1393-1396
Author(s):  
Zhi Peng Wu ◽  
Xue Dong Yang ◽  
Lei Bao

Prestressed high strength concrete pipe pile (PHC pile), a new type of pile, due to outstanding performance, widely used in various aspects of national construction, this paper introduces the development situation of prestress high strength concrete pile in our country, aiming at proposing own opinion in existence question in the construction process of high strength prestressed concrete pipe pile.


2016 ◽  
Vol 53 (4) ◽  
pp. 696-707 ◽  
Author(s):  
Hai-lei Kou ◽  
Jian Chu ◽  
Wei Guo ◽  
Ming-yi Zhang

A large-scale field testing program for the study of residual forces in pre-stressed high-strength concrete (PHC) pipe piles is presented in this paper. Five open-ended PHC pipe piles with 13 or 18 m in embedded length were installed and used for static loading tests at a building site in Hangzhou, China. All the piles were instrumented with fiber Bragg grating (FBG) strain gauges. The residual forces in these piles were recorded during and after installation. The measured load transfer data along a pile during the static loading tests are reported. The effect of the residual force on the interpretation of the load transfer behavior is discussed. The field data show that residual force along the installed pile increases approximately exponentially to the neutral plane and then reduces towards the toe. The residual force decreases with time to a stable value after pile jacking due to the secondary interaction between the pile and the disturbed soil around the pile and other factors. The large residual forces along the PHC pipe piles significantly affect the evaluation of the pile load distributions, and thus the shaft and toe resistances. The conventional bearing capacity theory tends to overestimate the shaft resistance at positions above the neutral plane and underestimate the shaft resistance at positions below the neutral plane, and the toe resistance for an open-ended PHC pipe piles founded in stratified soils.


Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Zhongjing Hu ◽  
Qingbiao Wang ◽  
Shuo Yang ◽  
Zhenyue Shi ◽  
Bo Liu ◽  
...  

Advancing urbanization in China requires large-scale high-rise construction and underground transportation projects. Consequently, there is an increasing number of deep foundation pits adjacent to water bodies, and accidents occur frequently. This study uses a numerical simulation method to study the stability of the deep foundation pit near water based on the Biot three-dimensional seepage-stress coupling model, with the open-cut section on the south bank of the Jinan Yellow River Tunnel Project as the engineering field test. This indicates the following: (1) the maximum horizontal displacement of the diaphragm wall occurred in the fifth excavation stage, and a horizontal brace effectively controlled the inward horizontal displacement of the foundation pit; (2) considering the effect of seepage in the soft soil foundation, the maximum vertical displacement of the ground surface at each excavation stage occurred adjacent to the underground continuous wall. As the depth of the foundation pit increased, the vertical surface settlement decreases gradually in the direction away from the excavation face; (3) considering the seepage conditions, within each interval of excavation of the foundation pit, the horizontal displacement of the continuous underground wall and ground settlement declined; and (4) the numerical simulation and field monitoring data were in good agreement. Under the conditions of accurate model simplification and parameter selection, numerical simulations can adequately forecast conditions of the actual project.


2012 ◽  
Vol 446-449 ◽  
pp. 718-727
Author(s):  
Hamid Reza Azizipesteh Baglo ◽  
Mohammed Raoof

In a number of previous publications, results were reported for a series of extensive and carefully conducted tests on large scale reinforced concrete (R.C.) beams with various extents of loss of concrete cover and exposure of main reinforcement along their spans, with such areas of simulated damage being located within their regions which are dominated by either shear or flexure. These tests on R.C. beams made with normal strength concrete have covered a wide range of first order beam design parameters, with their results used to verify the generality of various theoretical models. In the present paper, much attention will be devoted to various structural characteristics (such as ultimate strength, flexural stiffness, etc.) of similar damaged R.C. beams with the proviso that, instead of the previously used normal strength concrete, the beams are made with high strength concrete. No such results (for high strength R.C. beams) have previously been reported in the public domain.


2019 ◽  
Vol 945 ◽  
pp. 80-84
Author(s):  
O.E. Sysoev ◽  
A.Y. Dobryshkin ◽  
Ye.O. Sysoyev

The article is devoted to the investigation of pipe-concrete prestressed structural elements with high efficiency. This is due to a more complete use of the strength properties of structural materials in the pipe-concrete beam. The article presents various methods for calculating pipe-concrete elements. The design of a concrete tube with a prestressed element using high-strength concrete is presented. The results of calculations of various designs are shown and the cross-sections of beams for perception of the same bending load are selected. A comparison is made between the consumption of beam materials of various designs. The effectiveness of the use of pipe-concrete elements for receiving bending loads made of high-strength concrete with prestressed reinforcement is shown in comparison with the construction of beams of traditional high-strength concrete, high-strength concrete pipe-concrete with no prestressing of reinforcement and metal beam, mass of the element, consumption of metal and concrete.


2013 ◽  
Vol 405-408 ◽  
pp. 2511-2514
Author(s):  
Xian Rong ◽  
Jian Xin Zhang ◽  
Yan Yan Li ◽  
Yan Feng Chen

Based on the low cyclic loading experiments on prestressed high strength concrete pipe piles, in which one of them was reinforced by steel fiber, another stirrup ratio, the other was not reinforced, the authors compare the results in terms of damage characteristic, hysteretic curve, bearing capacity, displacement and ductility. It is shown that the bearing capacity and ductility of prestressed high strength concrete pipe piles reinforced by steel fiber increases. With the increase of stirrup ratio, the hysteretic behavior and the deformation behavior of prestressed high strength concrete pipe piles improves.


Sign in / Sign up

Export Citation Format

Share Document