Method of Estimation of Bearing Capacity of Multi-layer Pavements with Application of Quasi-static Tests

Author(s):  
Miroslaw Graczyk ◽  
Tomasz Mechowski ◽  
Jacek Sudyka ◽  
Maciej Chomicki ◽  
Józef Rafa
2010 ◽  
Vol 113-116 ◽  
pp. 2246-2250 ◽  
Author(s):  
Wang Li Zhang ◽  
Yu Shun Li ◽  
Huang Ying Shen ◽  
Tian Yuan Jiang ◽  
Zhen Wen Zhang

In order to promote building structure to be environmental friendly, light-weight and high-strength, a novel bamboo-steel composite wall is proposed. The composite wall is made up by sticking two pieces of bamboo plywood on the faces of a piece of profiled steel sheet utilizing structural glue. Taking thickness of the bamboo plywood and thickness and corrugation-height of the profiled steel sheet as variables, quasi-static tests were carried out on 5 specimens. Based on experimental phenomena and data, their earthquake resistant properties such as horizontal bearing capacity, ductility and energy dissipation and failure mechanism are analyzed. The results show that the bamboo plywood and profiled steel sheet can effectively work together, the composite walls possess wonderful seismic properties, and that changes of thickness or corrugation-height of profiled steel sheet make very sharp differences to the properties of the walls. Finally, a simplified mechanical model and calculation method for horizontal bearing capacity are proposed according to hysteresis curves within elastic range of these walls. The calculated values match well with the experimental ones.


Author(s):  
Rashid A. Mangushev ◽  
Nadezda S. Nikitina

The study describes the standard procedure of the assessment of the bearing capacity of piles by field methods used in the Russian Federation. Basing on the example of an experimental deep-laid foundation pile (length L = 65 m, diameter D = 1.2 m) intended for a high-rise building designed for a thick layer of loose ground the study demonstrates the structure of a loading system on site and the results of static tests of piles in comparison with the results of analytical and numerical calculations. On the same construction site an experimental barrette-pile of rectangular cross-section measuring 3.3 x 1.1 with a length of 65 m was installed with the base in solid Protero­zoic clays. The pile test was carried out using Osterberg cells. For this purpose in the process of the installation of the pile strain gauges were mounted in its reinforcing cage at 9 levels. The test barrette-pile was carried out in two stages. On the first stage a standard test of the whole pile in the top-down direction was performed (Top - Down). On the second stage, after reaching the maximum possible load, the “O - cell” element test was performed trans­mitting the load in two directions (up and down). “O - cell” was located at a depth of 50 m in the layer of blue- stone. The article contains the graphs of the movements of pile from under the load applied on the first and second stages of the tests and the general assessment of the load-bearing capacity of the barrette-piles by different methods


2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Lianjie Jiang ◽  
Guoliang Bai

The cumulative damage behavior of SRC columns under far-field long-period ground motions was simulated and studied by quasi-static tests with the same displacement for 10 times. Quasi-static tests of 8 SRC columns were conducted under the horizontal cyclic loading with the same displacement for 10 times or 3 times, and then the effects of steel ratio, stirrup ratio, axial compression ratio, and number of cyclic loading on the cumulative damage of SRC columns under the far-field long-period ground motions were studied. The results showed that the number of cyclic loading had little effect on the peak load of the specimens, but had a significant effect on the deformation capacity, stiffness degradation, and energy dissipation capacity. Compared with the specimens after 3 cycles, the displacement ductility coefficient of specimens after 10 cycles was reduced by about 20%–26%, the ultimate hysteresis energy dissipation was reduced by 35%–48%, while the stiffness degradation rate was accelerated. After the peak load, the cumulative damage caused by multiple cyclic loading with the same displacement was more significant, which aggravated the reduction of bearing capacity and stiffness degradation. The smaller the steel ratio and stirrup ratio, the larger the axial compression ratio, and the greater the reduction of the bearing capacity and stiffness of specimens. However, accumulated damage caused by multiple cyclic loading with the same displacement had a slight impact on the energy dissipation capacity. Increasing the steel ratio and stirrup ratio can effectively improve the deformation capacity and energy dissipation capacity of the specimens and reduce the bearing capacity and stiffness degradation caused by cumulative damage.


Author(s):  
I. Rybnikova ◽  
A. Rybnikov

Three methods for determining the load-bearing capacity of bored conical piles are presented, considering the additional forces of the ground rebound along their inclined side surface under vertical load. It is proposed to determine the bearing capacity according to the results of field tests using the coefficient of transition from the maximum permissible settlement of the building foundation to the settlement of the pile obtained during static tests. Its value varies from 0.1 to 0.3 depending on the angle of the pile taper. To determine the bearing capacity of the empirical method, tabular data of the ground rebound forces on the side surface of the piles are developed. It depends on the strength properties of the base soil, the angle of the pile taper and the depth of the location of the changing cross-section of the pile along the length. The process of compressing the soil in a drilled well with an elastic cylindrical pressiometer is close to the occurrence of a ground rebound when it is pushed apart by the side surface of a conical pile during sediment under load. It is proposed to determine the ground resistance on the side surface of conical piles according to the same dependence as when processing the results of pressiometric tests of soils, taking into account the introduction of a correction factor depending on the parameters of the pile. The calculated load-bearing capacity of the piles, determined by the proposed methods, differs from the actual load-bearing capacity, determined by the results of static tests of full-scale piles, within 10 %. However, these methods need to be improved with the accumulation of statistical data for testing full-scale piles in different ground conditions.


2011 ◽  
Vol 368-373 ◽  
pp. 189-192
Author(s):  
Liu He Cai ◽  
Wen Feng Li ◽  
Guo Wei Zhang ◽  
Qi Song Miao ◽  
Hui Wu

Quasi-static tests of three specimens of steel-concrete composite fabricated shear wall were performed to investigate its seismic behavior. The test results indicate that horizontal cracks run through the interface between the wall and the base beam, diagonal cracks appear on the whole prefabricated concrete shear wall. The specimens fail in the mode of bending-shear, the hysteretic curves according to the test were full, it means that they have better seismic bearing capacity.


2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Wei Huang ◽  
Xiang Ma ◽  
Bin Luo ◽  
Zeliang Li ◽  
Yujiao Sun

To develop new slabs with light weight and high rigidity as well as meet the requirements of use and facilitate construction, a large-span multi-ribbed composite slab (R-CS) with filled lightweight blocks is proposed based on systematic research. Static tests of the bending behaviour of the four pieces of the R-CS specimens and one ordinary concrete cast-in-place slab were carried out. The fracture distribution, bearing capacity, deflection, and load-strain curves of the tensile steel bars were analysed. The difference in the bending behaviour between the R-CS specimens and the cast-in-place slab and the influence of different structural forms on the bending behaviour of the R-CS samples were studied. By calculating the bearing capacity of the fully composite state, their composite performance was evaluated. The research shows that the bending failure process of the R-CS specimens is similar to that of the cast-in-place slab and the crack and deflection development as well as ductility are relatively good. The measured bearing capacity of the specimen can reach more than 70% of the theoretical calculation strength under the fully composite state. The composite performance is satisfactory.


2020 ◽  
Vol 8 (4) ◽  
pp. 22-27
Author(s):  
Pavel Gavrilov ◽  
Vyacheslav Glukhov

The purpose of this research is to estimate the bearing capacity of bored piles with broadening, formed by stone rolling. A series of static tests of the existing piles was performed in accordance with the requirements of the current regulatory documentation, the analysis of the obtained results was carried out. According to this experimental researches, was made a conclusion about the advisable to take into account the standard values of settlements at the determining of the bearing capacity of piles by ground. The results of field tests were compared with the calculated values, determined by calculation with the recommendations of SP 24.13330.2011. Noted, that the value of load, corresponding to the moment of the pile «failure», should be taken as a criterion of the factual bearing capacity.


2019 ◽  
Vol 97 ◽  
pp. 04030 ◽  
Author(s):  
Michał Baca ◽  
Włodzimierz Brząkała ◽  
Jarosław Rybak

A static load test of a pile provides information about the pile bearing capacity. Nevertheless sometimes more precise information can be needed, e.g. what part of load applied to the pile is carried by its base and its shaft. Many kinds of bi-directional static tests offer the possibility of a separate investigation of the behaviour of pile base and shaft. In these tests, however, the shaft works in a different direction than in actual pile working conditions. In this paper, the authors focus on the results of a static load test on model piles, which make it possible to solely investigate the pile base capacity. The paper describes the construction of a test stand and the testing procedure, and presents the first results of the preformed tests.


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