scholarly journals ESTIMATION OF SUBGRADE REACTION COEFFICIENT FOR HORIZONTALLY LOADED PILES BY STATISTICAL ANALYSES

2005 ◽  
Vol 45 (3) ◽  
pp. 51-70 ◽  
Author(s):  
YUSUKE HONJO ◽  
YULVI ZAIKA ◽  
GYANESWOR POKHAREL
Keyword(s):  
Statistical Analyses ◽  
Subgrade Reaction ◽  
Reaction Coefficient

scholarly journals Laboratory Tests for Subgrade Reaction Coefficient in Seismic Design of Underground Engineering Domain

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Kunpeng Xu ◽  
Liping Jing ◽  
Xinjun Cheng ◽  
Haian Liang ◽  
Jia Bin
Keyword(s):  
Seismic Design ◽  
Shaking Table Test ◽  
Free Field ◽  
Deformation Mode ◽  
Shaking Table ◽  
Subgrade Reaction ◽  
Underground Structures ◽  
Testing Methods ◽  
Underground Engineering ◽  
Reaction Coefficient

Subgrade reaction coefficient is commonly considered as the primary challenge in simplified seismic design of underground structures. Carrying out test is the most reliable way to acquire this intrinsic soil property. Owing to the limitations of experimental cost, time consumption, soil deformation mode, size effect, and confined condition, the existing testing methods cannot satisfy the requirements of high-precision subgrade reaction coefficient in seismic design process of underground structures. Accordingly, the present study makes an attempt to provide new laboratory testing methods considering realistic seismic response of soil, based on shaking table test and quasistatic test. Conventional shaking table test for sandy free-field was performed, with the results indicating that the equivalent normal subgrade reaction coefficients derived from the experimental hysteretic curves are reasonable and verifying the deformation mode under seismic excitation. A novel multifunctional quasistatic pushover device was invented, which can simulate the most unfavorable deformation mode of soil during the earthquake. In addition, the first successful application of an innovative quasistatic testing method in evaluating subgrade reaction coefficient was reported. The findings of this study provide preliminary detailed insights into subgrade reaction coefficient evaluation which can benefit seismic design of underground structures.

Estimation of horizontal subgrade reaction coefficient by inverse analysis

2008 ◽  
Vol 35 (4) ◽  
pp. 616-626 ◽  
Author(s):  
N. Kobayashi ◽  
T. Shibata ◽  
Y. Kikuchi ◽  
A. Murakami
Keyword(s):  
Inverse Analysis ◽  
Subgrade Reaction ◽  
Reaction Coefficient

scholarly journals Estimating an empirical equation connecting subgrade reaction modulus with cone penetration test for sandy soils

2021 ◽  
Vol 9 (2) ◽  
pp. 001-008
Author(s):  
Abdelaziz Ahmed Bohagr ◽  
Ghassan Ahmed El gehani ◽  
Mohammed Mahmoud Boudejaja ◽  
Mustafa M Amami
Keyword(s):  
Sandy Soils ◽  
Cone Penetration Test ◽  
Shape Effect ◽  
Subgrade Reaction ◽  
Penetration Test ◽  
Cone Penetration ◽  
Loading Test ◽  
Reaction Coefficient ◽  
Tip Resistance ◽  
Load Tests

In geotechnical engineering, the coefficient of subgrade reaction is regarded as one of the most important parameters used for describing the interaction of soil and structure as well as describing some soil characteristics, subgrade reaction coefficient can be calculated theoretically using many different formulas, laboratory via specific well-known tests, and in site through field plate loading test. On the other hand, the cone penetration test is one of the most frequently used field tests to investigate the soil. The lately carried out researches showed a good relation between the subgrade coefficient and the tip resistance collected from the CPT, but the results obtained from the proposed method are still doubtable. In this paper, fifteen plate load tests and thirty CPTs, already collected for private site investigation project, have been used for finding the best fit equation connecting the subgrade reaction coefficient Ks with the tip resistance qc. The finds of the established equation have been compared extensively with those of other well-known related equations. The results show the ability of the concluded equation to get Ks results in the acceptable range of sandy soils. However, the depth and shape effect on the suggested formula need further investigations since all the plate load tests in this project have been carried out on the soil surface with a 45 cm diameter circular plate.

Shield Tunnel Structure Modal Analysis with Floating Slab Track on Elastic Foundation

2013 ◽  
Vol 838-841 ◽  
pp. 1393-1398
Author(s):  
Li Kang ◽  
Zhen Yu Lei
Keyword(s):  
Elastic Foundation ◽  
Concrete Slab ◽  
Element Model ◽  
Equivalent Model ◽  
Shield Tunnel ◽  
Subgrade Reaction ◽  
Slab Track ◽  
Reaction Coefficient ◽  
Geological Conditions ◽  
Spring Support

A finite element model (FEM) was proposed to analyze the model of floating slab track (FST) system based on elastic foundation in shield tunnel, and the equivalent model of continuous girder and theory of beam on elastic foundation were considered. Floating concrete slab eigenfrequencies can be calculated under the various combinations of subgrade reaction coefficient, steel spring support stiffness, fastener stiffness and thickness of the floating slab. The results show that geological conditions had certain effects on the eigenfrequencies of FST.

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