scholarly journals A Full-Scale Experimental Study of the Vertical Dynamic and Static Behavior of the Pier-Cap-Pile System

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Jianlei Liu ◽  
Meng Ma ◽  
Flavio Stochino
Keyword(s):  
Experimental Study ◽  
Bearing Capacity ◽  
Dynamic Stiffness ◽  
Soil Layer ◽  
Low Frequency ◽  
Full Scale ◽  
Single Pile ◽  
Static Stiffness ◽  
Loading Test ◽  
Test Technique

The bearing capacity evaluation of bridge substructures is difficult as the static loading test (SLT) cannot be employed for the bridges in services. As a type of dynamic nondestructive test technique, the dynamic transient response method (TRM) could be employed to estimate the vertical bearing capacity when the relationship between static stiffness and dynamic stiffness is known. The TRM is usually employed to evaluate single piles. For the pier-cap-pile system, its applicability should be investigated. In the present study, a novel full-scale experimental study, including both TRM test and SLT, was performed on an abandoned bridge pier with grouped pile foundation. The test included three steps: firstly, testing the intact pier-cap-pile system; then, cutting off the pier and testing the cap-pile system; finally, cutting off the cap and testing the single pile. The TRM test was repeatedly performed in the above three steps, whereas the SLT was only performed on the cap-pile system. Based on the experimental results, the ratio of dynamic and static stiffness of the cap-pile system was obtained. The results show that (1) in the low-frequency range (between 10 and 30 Hz in this study), the dynamic stiffness of the whole system is approximately four times of that of a single pile; (2) the ratio of dynamic and static stiffness of the cap-pile system tested in the study is approximately 1.74, which was similar to other tested values of a single pile; (3) to evaluate the capacity of similar cap-pile system and with similar soil layer conditions by TRM, the value of Kd/Ks tested in the study can be used as a reference.

Experimental Study on the Performance of the Laminated Steel Isolators

2013 ◽  
Vol 423-426 ◽  
pp. 1603-1607
Author(s):  
Yao Guo Xie ◽  
Ping He ◽  
Xian Qiang Qu ◽  
Hong Bin Cui
Keyword(s):  
Experimental Study ◽  
Vibration Isolation ◽  
Dynamic Stiffness ◽  
Damping Ratio ◽  
Dynamic Performance ◽  
Performance Testing ◽  
Stiffness Ratio ◽  
Static Stiffness ◽  
Comparison Of The Results

Through the analysis and comparison of the results of static and dynamic performance testing of a series of laminated steel pieces isolators used in the vibration isolation of warships, in the number and thickness of laminated steel pieces of the same circumstances, laminated steel arc and preload of test samples had a certain impact on the values ​​of static stiffness, dynamic stiffness, damping ratio as well as dynamic and static stiffness ratio.

scholarly journals Experimental study on horizontal bearing capacity of enlarged cap-group pile composite foundation

2019 ◽  
Vol 136 ◽  
pp. 04066
Author(s):  
Taihao Chen ◽  
Yiming Xu ◽  
Jie Chen
Keyword(s):  
Experimental Study ◽  
Bearing Capacity ◽  
Load Sharing ◽  
Composite Foundation ◽  
Single Pile ◽  
Horizontal Load ◽  
Horizontal Resistance ◽  
Pile Cap ◽  
Large Wind ◽  
Group Pile

In order to provide reference for the engineering design in the area with large wind, water flow and other horizontal loads, the experimental study on the horizontal bearing capacity of composite foundation under three different working conditions was carried out in this paper, which includes cap-single pile, cap-9 piles and enlarged cap-9 piles. The results show that under the condition of cap-9 piles, the group pile effect coefficient is 1.17, and the load sharing ratio of the back piles is the largest, and the middle and front piless decrease sequentially. Also, with the increase of horizontal load, the load sharing ratio of the back pile increases while the middle and front piless is decremented. Under the condition of enlarged cap-9 piles, the group pile effect coefficient is 1.36, which is 16.24% higher than that of the cap-9 piles, which means the horizontal resistance is obviously enhanced. At the same time, compared with the cap-9 piles, the load sharing ratio of the back pile is reduced while the middle and front piless is increased, which means the stress of pile body tends to be more uniform.

Experimental study on dynamic performance of typical nonballasted track systems using a full-scale test rig

2016 ◽  
Vol 231 (4) ◽  
pp. 470-481 ◽  
Author(s):  
Mingze Wang ◽  
Chengbiao Cai ◽  
Shengyang Zhu ◽  
Wanming Zhai
Keyword(s):  
Experimental Study ◽  
Dynamic Stiffness ◽  
Dynamic Performance ◽  
Full Scale ◽  
Damping Coefficient ◽  
Full Scale Test ◽  
Test Rig ◽  
Scale Test ◽  
Stiffness And Damping Coefficient ◽  
Stiffness And Damping

This paper presents an experimental study on dynamic performance of China Railway Track System (CRTS) series track systems using a full-scale test rig. The test rig has been constructed based on 55.17 m long full-scale nonballasted tracks composed of four typical CRTS track elements in high-speed railways. First, the dynamic characteristics of different nonballasted tracks are investigated by conducting wheel-drop tests, where a wheel-drop testing vehicle with a dropping wheelset is devised to provide the wheel-drop load. The vibration levels of different track systems are assessed by the root-mean-square acceleration per one-third octave band, and the vibration transmission characteristics of the CRTS series tracks are evaluated by transfer functions. Further, a mathematical track model is used to extract the dynamic stiffness and damping coefficient of the four types of nonballasted track systems based on the wheel–rail impact response. The vibration characteristics, the dynamic stiffness, and damping coefficient of different nonballasted track systems under various wheel-drop heights are compared and discussed in detail.

scholarly journals Full-Scale Well Instrumented Large Diameter Bored Pile Load Test in Multi Layered Soil: A Case Study of Damietta Port New Grain Silos Project

2018 ◽  
Vol 8 (01) ◽  
Author(s):  
M. Eid ◽  
A. Hefny ◽  
T. Sorour ◽  
Y. Zagh
Keyword(s):  
Load Distribution ◽  
Large Diameter ◽  
Soil Layer ◽  
Full Scale ◽  
Layered Soil ◽  
Load Test ◽  
Test Field ◽  
Loading Test ◽  
Bored Pile ◽  
Pile Load Test

A Large diameter bored pile with diameter of 1.00 m and length of 34.00 m has been implemented in multi layered soil. The pile was tested under three axially loading and unloading cycles, in order to determine the load settlement curve and assess the ultimate pile capacity. Extensive investigation was carried out to obtain reliable soil properties at the examined pile location, through in situ and laboratory soil tests. Twelve strain gauges were fixed on pile steel reinforcement bars at top of each soil layer level. Moreover, four dial gauges were set up at pile head. Also, three telltales were extended to three different levels inside the pile. The pile load test field measurements are presented in the form of load settlement and load distribution curves for different loading steps. In addition, the pile ultimate capacity is calculated using different codes criterions and compared with the loading test results. Large diameter bored pile, Settlement, Pile load distribution, Pile installation, Instrumentation, Full scale pile load test, Pile behavior.

A Simplified Computational Method of Lateral Dynamic Impedance of Single Pile

2011 ◽  
Vol 243-249 ◽  
pp. 2985-2989
Author(s):  
De Sen Kong ◽  
Yan Qing Men ◽  
Li Hua Wang
Keyword(s):  
Dynamic Stiffness ◽  
Soil Layer ◽  
Computational Method ◽  
Soil Dynamics ◽  
Single Pile ◽  
Softening Effect ◽  
Dynamic Impedance ◽  
Stiffness And Damping ◽  
The Comparative Study ◽  
Soil Interface

Research of the pile-soil interaction effect is a complicated issue in civil engineering. Using the principle of soil dynamics and structural dynamics, a simplified computational method for computing the lateral dynamic impedance of single pile embedded in layered non-homogeneous subsoil is established based on a certain assumptions. Both non-homogeneity of soil strata and softening effect of soil layer around pile during vibration as well as separation of pile-soil interface are simultaneously taken into account in the proposed computational method. The characteristics of the frequency-dependency of lateral dynamic stiffness and damping of pile are reproduced. It is shown through the comparative study on a numerical example that the numerical results of dynamic impedance of pile computed by the proposed method are relatively rational and can well agree with the computational and experimental results currently available.

scholarly journals An Analysis of Static Load Test on Sinngle Square Pile of 50 x 50 cm2 Using Finite Element Method in Multy-Storey Building Project , Pluit, North Jakarta

2020 ◽  
Vol 2 (1) ◽  
pp. 49-62
Author(s):  
Riki Octavia Rusland
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Bearing Capacity ◽  
Empirical Method ◽  
Single Pile ◽  
Loading Test ◽  
Building Project ◽  
Group Pile ◽  
Storey Building ◽  
Element Method

Planning a foundation for a high building and carrying a large construction burden, must be carried out with a correct, thorough and comprehensive analysis, so that a foundation design is able to carry the burdens that works on it and can carry the loads it receives to ground beneath it safely. This study analyzed the capacity of bearing capacity and the settlement of the hydraulic stressed pile foundation of prestressed concrete square pile of 50 x 50 cm2 in cross section of single pile or group pile. The research used empirical method, finite element method program and compared the results with the interpretation of axial static loading test on the Multy-Storey Building Project in Pluit, North Jakarta. The analysis used soil investigation and laboratory study and used 2D and 3D finite element methods by Mohr-Coulomb and Soft soils models. The result of the analysis on the ultimate bearing capacity of hydraulic stressed pile foundation with empirical method of Meyerhof gave the highest value using SPT data at DB1 borelog point of 655.23 tons, and the lowest was the result of interpretation of Loading Test by Davisson’s method of 260.00 tons. The ultimate bearing capacity required by ASTM D1143-81 (1989) for the Static Axial Loading Test is 300 tons (200% of working load), while the interpretation of the Davisson’s Loading Test method (260.00 tons), Chin (267,86 tons) and Mazurkiewicz (267.00 tons), none of which have fulfilled the requirements for carrying 150 tons of working load. The lateral bearing capacity of Broms method was 16,14 tons which was the strength of the pile material against lateral loads. Whereas for the bearing capacity of the group pile ( 6 points in one pilecap) the lowest efficiency of 0,734 from the Converse-Labarre Equation and the highest efficiency of 0,805 from the Los Angeles Group Action Equation was obtained. For 200% of the planning load of 150 tons, that is 300 tons, the settlement of the single pile which occurred from 2D finite element method program were 18,00 mm and 15,63 mm for 3D while the results of the Loading Test was 15,00 mm. The results of the analysis of Loading Test settlement was more realible.

scholarly journals EXPERIMENTAL STUDY OF FULL-SCALE STATIC LOADING TEST ON WOODEN KING-POST TRUSSES USING PRE-CUT SYSTEM FOR FRAMEWORK OF WOODEN HOUSE SPACE

2017 ◽  
Vol 23 (54) ◽  
pp. 481-486
Author(s):  
Hirohide TAO ◽  
Kenta SASAKI ◽  
Hiro KAWAHARA ◽  
Masahiro INAYAMA ◽  
Kazuhiko FUJITA
Keyword(s):  
Experimental Study ◽  
Static Loading ◽  
Full Scale ◽  
Loading Test ◽  
Wooden House ◽  
Static Loading Test

Experiment Study on Bearing Capacity of Muddy Siltstone Foundation and its Application

2013 ◽  
Vol 838-841 ◽  
pp. 101-106
Author(s):  
Dong Sheng Yang
Keyword(s):  
Theoretical Analysis ◽  
Bearing Capacity ◽  
Skin Friction ◽  
Static Loading ◽  
Soft Rock ◽  
Single Pile ◽  
Experiment Study ◽  
Loading Test ◽  
Static Loading Test

Rock-socket cast-in-situ piles is a commonly used style of foundation, but theoretical analysis, experiments and test research of bearing capacity behavior about rock-socket piles in soft rock have not adapted to the requirement of engineering. The static loading test of single pile on a project in argillaceous and silt laminate, through which the skin friction and point bearing capacity were measured, the bearing capacity behavior of rock-socket cast-in-situ piles in soft rock was analyzed.

Bearing capacity and settlement of weak fly ash ground improved using lime – fly ash or stone columns

2002 ◽  
Vol 39 (3) ◽  
pp. 585-596 ◽  
Author(s):  
Cheng Zhou ◽  
Jian-Hua Yin ◽  
Jing-Ping Ming
Keyword(s):  
Shear Strength ◽  
Fly Ash ◽  
Bearing Capacity ◽  
Negative Impact ◽  
Soil Layer ◽  
Stone Columns ◽  
Small Scale ◽  
Loading Test ◽  
Foundation Soil ◽  
Physical Tests

An experimental study was conducted to evaluate the suitability of lime for the improvement of weak fly ash ground. In the study, a series of unconfined and confined compression tests were carried out on cylindrical samples in the laboratory and on cubic samples in the field, of Lime-FA (lime – fly ash) mixtures with various mixing contents of lime and curing times. Some samples were compressed under a soaking condition with water. A series of full-scale physical tests in the field and small-scale physical tests in the laboratory were conducted on a foundation (or rigid plate) on weak fly ash ground improved using Lime-FA or stone columns, which form a composite foundation. Some physical tests were carried out under a soaking condition. From the test and physical model study, it was found that the Lime-FA mixture has a larger shear strength than that of fly ash when the mixing content of lime is larger than 10%. When the weak fly ash ground is improved with Lime-FA columns, the bearing capacity of the fly ash ground is increased, and the settlement is reduced largely. However, when the ground is soaked under water, the corresponding shear strength of the Lime-FA mixture is decreased, the bearing capacity of the Lime-FA composite ground is decreased, and the settlement is increased. A plate loading test with soaking test on a layer of 1.15 m thick fly ash was also done in the laboratory. The test results show that the top fly ash layer is not suitable as a foundation soil layer and should be replaced with other granular soils, rather than simply compacted to a higher density, due to the negative impact of soaking. Results from the test program are presented and discussed.Key words: fly ash, lime, unconfined compressive strength, shear strength, bearing capacity, settlement, soaking.

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