scholarly journals Experimental and Application Study on Underpinning Engineering of Bridge Pile Foundation

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Lei Yan ◽  
Gang Wang ◽  
Min Chen ◽  
Kefeng Yue ◽  
Qingning Li

In order to study the theory and application of the pile foundation underpinning technology, 3 local node models of underpinning structures with a similarity ratio of 1/1 were made and the progressive repeated static loading tests were conducted. The shear and antislip properties of the joint are studied, and the improved formula for calculating the shear capacity is proposed. The results show that a planting bar plays a major role in shear resistance, and the hoop rate can improve the shear capacity of the interface. The new formula for calculating the shear-bearing capacity is proposed, and the calculation results of the formula of shear-bearing capacity are in good agreement with the experiment results. It is completely feasible to use this formula to calculate the shear-bearing capacity of the pile foundation underpinning structure. During the test, the bearing capacity of the model is good, which proves the reliability of the underpinning technology is good, and it can provide experimental and theoretical basis for the underpinning of similar projects.

2012 ◽  
Vol 455-456 ◽  
pp. 1079-1083
Author(s):  
Wei Jun Yang ◽  
Hong Jia Huang ◽  
Wen Yu Jiang ◽  
Yi Bin Peng

Shantou atmospheric salt-fog environment is simulated with the comprehensive salt spray test chamber. By using reinforced concrete short beams under different water-cement radio, different corrosion time, the inclined section degradation rules of the corrosive reinforced concrete members are researched for establishing shear capacity of short beam formulas in salt-fog environment.


2011 ◽  
Vol 368-373 ◽  
pp. 2175-2179
Author(s):  
Tian Lai Yu ◽  
Hong Kun Han ◽  
Xin Yu Li ◽  
Qiang Ma

The shear resistant with SWR (steel wire rope) external prestressing is a kind of new type of reinforcement technique. The advantages of the method are ideal reinforcement effect, durability, and convenient construction. So the method has been paid attention by more and more scientists and technical workers. Through the experiment of 1 basic beam and 3 strengthened beams which are in different dead load levels, the influence of damage degree of original beams and the dead load level of strengthened beams are analyzed. The reduction coefficient values of shear capacity under different dead load level are researched. The research is shown that: with the dead load level increasing, the improve degree of shear capacity of strengthened concrete beams is smaller. The mathematical model is established, which is about dead load level and reduction coefficient of shear capacity of strengthened concrete beams. The result is to take 0.75 as the reduction coefficient of shear capacity. The value is reasonable in calculating the shear bearing capacity of strengthened beams under dead load.


2020 ◽  
Vol 198 ◽  
pp. 02017
Author(s):  
Zhongju Feng ◽  
Shaofen Bai ◽  
Wu Min ◽  
Jingbin He ◽  
Zhouyi Huang ◽  
...  

In order to study the influence of steep slope-karst coupling on the vertical bearing characteristics of pile foundation, the orthogonal simulation tests of pile foundation under 4 different roof thickness and 5 different slope are carried out by using Marc finite element software, and the correction coefficient of vertical partial bearing capacity of pile foundation according to roof thickness and slope is put forward. The test results show that when the thickness of the roof is more than 3 times the pile diameter, the ultimate bearing capacity of the pile foundation tends to be stable, and the value is about 19% when the slope is 45°; the ultimate bearing capacity of the pile foundation decreases gradually with the increase of the slope, and the reduction reaches 29.83% when the slope is greater than 45°. According to the calculation results, the variation law of vertical partial bearing capacity of pile foundation is analyzed, and the calculation formula of standard value of vertical ultimate bearing capacity of pile foundation in steep slope karst area considering both roof thickness and slope is put forward, and the correction coefficients αi and β are put forward.


Author(s):  
Nusa Setiani Triastuti ◽  
Indriasari Indriasari

<p><em>Pile foundation is one of the solutions of high-rise buildings not in the area of restrict area. When the pile foundation reached until the hard ground reaches, a small settlement is expected and  different  setlement  are  not occur. The objective: analyze the results of loading tests compared carryng capacity calculations, pile cap thick required secure.</em></p><p><em>The research method used in this research is the case study of pile foundation  twelve floors building in Batam island. The reaction on the pile is analyzed using software program of non-linear structure version 9.5 which is supported by primary data, namely loading test and secondary data of soil investigation and the largest column force taken on the pole 1.618,854 ton, Mx -7,936 ton meter, My -75,531 ton meter.</em></p><p><em>Carrying capacity analysis is based on friction and end bearing and calculated pole efficiency. The axial load of the plan is supported by 16 (sixteen) piles, based on the loading test (P) the ultimate pile foundation reaches 200% (two hundred percent) in the amount of 411.52 tons. </em><em>Single pile carrying capacity is 205.76 tons .Settlement in the loading test results 10mm is smaller than from the setlement in calculation results. The stress acting on the pile cap of 12.453 kg/cm<sup>2</sup> is smaller than the permit strees of 13 kg/cm<sup>2</sup>.</em></p>


2020 ◽  
Vol 980 ◽  
pp. 266-274
Author(s):  
Jian Hua Xiao ◽  
Miao Liu ◽  
Jin Li Wang ◽  
Abdulhamid Yakubu Anvah

In order to investigate the shear capacity of prefabricated beam, experiments about shear bearing were performed on one integral pouring contrast beam and two prefabrication and assembly beams. Inspecting the relationship between load and deflection under the load, the development regularity of strain between longitude reinforced and stirrup, the shear capacity of cracking load and ultimate bearing capacity, analyzing failure mode of oblique section and connection performance of old and new concrete in the groove, and compared with the mechanical properties of cast-in-place concrete beam. The experimental results indicate that: prefabrication and assembly beam and cast-in-place beams have similar shear bearing capacity and failure mode of oblique section, along with the load level continues to increase, the groove joint stiffness weakened, but has little effect on the overall deformation.


2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Yongjun Lin ◽  
Kaiqi Liu ◽  
Tianxu Xiao ◽  
Chang Zhou

In this paper, in order to investigate the shear mechanism and shear capacity of framework joints of steel-reinforced concrete-filled circular steel tube (SRCFCST), a numerical finite element model reflecting the mechanical behavior of framework joints of SRCFCST column-reinforced concrete beam is established through simulating concrete by the damage plastic constitutive model and simulating steel by the ideal elastic-plastic material, and its effectiveness is verified by experimental data. On account of uniform distribution of circular steel reinforced around the section and without definite flange and web, the shear mechanism of the framework joints of SRCFCST is analyzed on the basis of equivalent circular steel tube (CST) to the rectangular steel tube. The method for calculating the superposed shear bearing capacities of the joint core area is proposed, which is composed of four parts, i.e., concrete inside tube, concrete outside tube, hooping and steel-reinforced web; and the corresponding formulas for calculating shear bearing capacity are established. The comparative analysis of joints’ shear bearing capacity indicates that the results of numerical simulation and shear bearing capacity formulas coincide well with the experimental values, which can provide reference for the nonlinear analysis and engineering design of similar joints.


2021 ◽  
Vol 1020 ◽  
pp. 93-103
Author(s):  
Xi Kang Yan ◽  
Shun Zhang ◽  
Guo Liang Zhao ◽  
Xiao Chen ◽  
Bei Zhang

The construction joint is the weak part of the structure, and the P-δ effect is mostly ignored when considering the second-order effect, so it is necessary to study the influence of second-order effect on frame columns. Based on the above considerations, under different axial compression ratios, the mechanical properties of the construction joints of the frame columns with construction joints and the cast-in-situ frame columns were studied by low cycle repeated load testsand analyzed the influence of the second-order effect on the shear capacity of frame columns with joints. The test results indicate that the existence of construction joints reduces the shear-bearing capacity of the specimens, and the second-order effect has a greater impact on the columns with joints under the same axial compression ratio, and the shear capacity decreases more. With the increase of the axial compression ratio, the second-order effect will be weakened on the frame column with seam, but when the axial compression ratio exceeds a certain limit, the second-order effect will be increased.


2012 ◽  
Vol 487 ◽  
pp. 232-236
Author(s):  
Xu Feng Jiang ◽  
Meng Guo ◽  
Cheng Hao Wu

In order to enhance the anti-seismic performance of the frame structure and masonry structure with frame at bottom layer, combined shear wall consisting of frame and gridiron composite wall was proposed in this paper, and shear bearing capacity calculation method for the wall was researched. 1/2 scale frame-sparse gridiron composite walls were tested under reversed cyclic loading. Damage processes, load-bearing capacity and hysteretic curves characters of the walls were analyzed. Based on the experiments and reinforced concrete masonry walls data, the force features and shear resistance mechanism of the wall were analyzed, and general shear bearing capacity formula were put forward, and application methods under different conditions were given at the same time. Comparative analysis between calculation results and test results indicated that the formula was accurate enough, and can be referred to in the new construction and post-quake reconstruction of frame structure or masonry structure with frame at bottom layer.


2020 ◽  
Vol 9 (1) ◽  
pp. 70-77
Author(s):  
Amanda Rachmad Pratama ◽  
Rida Respati ◽  
Norseta Ajie Saputra

Soil bearing capacity is the ability of the soil to support the foundation load acting on it. To produce an accurate bearing capacity, it is necessary to know the properties and characteristics of the soil. For this reason, a comparison of the carrying capacity of the soil is carried out based on the calculation of CPT / Sondir and SPT to be able to plan a safe and economical pile foundation. The purpose of this study was to determine the amount of soil bearing capacity of the deep foundation in the environment around the Ataqwa Mosque, Baringin Village, Palangkaraya City based on field tests, and based on laboratory tests, and to determine the value of the comparison between the Mayerhof Method and the Schmertmann-Nottingham Method. Based on the Sondir value, it is continued with the calculation of the carrying capacity of the soil, then the calculation results are analyzed and concluded. From the calculation of the value of the carrying capacity of the foundation pile implementation of point 1 (one), the highest value of 400 mm diameter piles in the Meyerhoff method is 75,319 kg, while the lowest bearing capacity value is also at 400 mm piles of 10,676 kg. For point 2 (two), the highest value is obtained at 400 mm diameter piles in the Shmertmann-Nottingham method of 65,853 kg, while the lowest bearing capacity value is also at 400 mm piles of 10,676 kg


2020 ◽  
Vol 198 ◽  
pp. 02002
Author(s):  
Sun Jianzhong ◽  
Guo Chunxiang ◽  
Wang Xu ◽  
Zhang Weijia

Bore Cast-in-place Piles broke the original water and heat balance state of the stratum in the bridge construction of Qinghai Tibet railway. The settlement of a bridge pile foundation was relatively large after more than ten years of operation. It was found that there is confined water in the foundation soil after investigation. Engineers planned to add auxiliary piles at the original pile side to reduce the settlement of the pile foundation.This paper studied the temperature change, bearing capacity formation rule and long-term bearing capacity change trend of the new pile-soil system after adding auxiliary piles on the original foundation, which provides certain theoretical basis and reference basis for engineering practice. A three-dimensional model of a bridge pile foundation was established by numerical method. Considering the influence of atmospheric temperature, hydrogeological conditions, concrete temperature into the mold, and the temperature of underground confined water, based on the heat transfer theory, the boundary conditions and initial conditions are given. The influence of the change of ground temperature field and the change of pile-soil interface temperature on the bearing capacity of the foundation was studied after the auxiliary pile was poured. The analysis shows that the measure to increase the bearing capacity by adding auxiliary piles is a double-edged sword. On the one hand, the auxiliary piles themselves constitute the bearing capacity together with the original pile foundation after thawing, on the other hand, the auxiliary piles are constructed by the method of pouring concrete in the field. The hydration heat of concrete makes the temperature of the original foundation soil rise, and reduces its bearing capacity. The whole bearing capacity will not be increased at the initial stage, but also will be temporarily reduced, and the whole bearing capacity will be formed after the frozen soil is frozen back in the later stage.


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