Model Test Research on Bearing Behavior of Improved Over-Wet Soil

2011 ◽  
Vol 261-263 ◽  
pp. 1009-1013
Author(s):  
Song Gu ◽  
Hua Wen ◽  
You Wen Su ◽  
Bin Jia
Keyword(s):  
Boundary Condition ◽  
Bearing Capacity ◽  
Model Test ◽  
Similarity Theory ◽  
Water Stability ◽  
Test Results ◽  
Similar Model ◽  
Mixing Method ◽  
The Difference ◽  
Bearing Behavior

According to the similarity theory, this paper presents a similar model with the similar geometric load and boundary condition to analyze the difference between untreated over-wet soil in Ya’an and improved over-wet soil. The test results show: the bearing capacity of improved soil is enhanced; the settlement of improved soil is much less than which of unimproved soil; the water stability of improved soil is strengthened. These means we have achieved the purpose of improving over-wet soil and the ash mixing method is a feasible means for dealing with over-wet soil.

Model Test Studies of the Vertical Bearing Behavior of Bored Piles with Breakage Defects

2012 ◽  
Vol 256-259 ◽  
pp. 65-70
Author(s):  
Cheng Hua Wang ◽  
Juan Su ◽  
Gan Wang
Keyword(s):  
Bearing Capacity ◽  
Model Test ◽  
Great Influence ◽  
Test Results ◽  
Sudden Drop ◽  
Bored Piles ◽  
Vertical Bearing ◽  
Vertical Bearing Capacity ◽  
Bearing Behavior

In order to study the vertical bearing behavior of bored piles with breakage defects, a series of methods for simulation of normal piles and broken piles in laboratory was developed and used to investigate the vertical bearing behavior of these piles. The load-settlement curves of normal piles and broken piles were measured and analyzed. The tests revealed that the upper part of a broken pile works alone as a short pile before it contact with the lower part of the pile at the end of the first sudden drop stage.The analysis of the test results showed that the position of the breakage defect has a great influence on the lost in vertical bearing capacity of the pile.

Algorithm and Experiment of the Separated Foundation Bearing Capacity of Culverts Considering Lateral Fill

2012 ◽  
Vol 450-451 ◽  
pp. 1616-1624
Author(s):  
Wen Lu Wang ◽  
Shu Jun Cui ◽  
Da Jun Zhao ◽  
Lei Wang
Keyword(s):  
Bearing Capacity ◽  
Model Test ◽  
Similarity Theory ◽  
Calculation Model ◽  
Test Results ◽  
Foundation Soil ◽  
Model Experiments ◽  
M 10 ◽  
Foundation Deformation ◽  
M 12

How to determine the foundation bearing capacity of high-stacked culverts in highway construction becomes a problem that must be taken seriously. Combining with the stress characteristics of the foundation soil, the soil force was analyzed for finding the improved effect on the separated foundation bearing capacity of lateral fill. Establishing the calculation model and algorithm, the general formulation of separated foundation bearing capacity considering lateral fill was deduced. Then under direction of similarity theory, six model experiments were designed to simulate the silt clay foundation deformation in whole loading process. The pressure-settlement curves were drew and the foundation bearing capacity under lateral fill height of 0 m, 4 m, 6 m, 8 m, 10 m, 12 m were measured. Test results showed that with the fill height increasing the bearing capacity increased significantly, it had been reached 815 kPa when the fill height was 10 m. But the growth was nonlinear, it first increased from 18.40% to 20.37% and then reduced to 8.59%. At last the bearing capacity reached 885 kPa while fill height exceeded 12 m. Meanwhile the errors between the calculated results and measured by model test were almost less than 10% so the algorithm was feasible. The conclusion is that the lateral fill is advantageous for improve the foundation bearing capacity and reduce project cost significantly when the settlement of the culverts foundation satisfied the design request, with the lateral fill increasing, the rate of the improvement first increases and then decreases, at last it tends to 885 KPa when fill height exceeded 12 m.

Ultimate bearing capacity of shallow foundations on sand with geogrid reinforcement

1993 ◽  
Vol 30 (3) ◽  
pp. 545-549 ◽  
Author(s):  
M.T. Omar ◽  
B.M. Das ◽  
V.K. Puri ◽  
S.C. Yen
Keyword(s):  
Bearing Capacity ◽  
Key Words ◽  
Model Test ◽  
Ultimate Bearing Capacity ◽  
Shallow Foundations ◽  
Shallow Foundation ◽  
Laboratory Model ◽  
Critical Depth ◽  
Test Results ◽  
Laboratory Model Test

Laboratory model test results for the ultimate bearing capacity of strip and square foundations supported by sand reinforced with geogrid layers have been presented. Based on the model test results, the critical depth of reinforcement and the dimensions of the geogrid layers for mobilizing the maximum bearing-capacity ratio have been determined and compared. Key words : bearing capacity, geogrid, model test, reinforced sand, shallow foundation.

Stabilization of Weak Clay with Strong Sand and Geogrid at Sand-Clay Interface

1998 ◽  
Vol 1611 (1) ◽  
pp. 55-62 ◽  
Author(s):  
Braja M. Das ◽  
Kim H. Khing ◽  
Eun C. Shin
Keyword(s):  
Bearing Capacity ◽  
Model Test ◽  
Soil Layer ◽  
Granular Soil ◽  
Laboratory Model ◽  
Test Results ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Base Course ◽  
Granular Base

The load-bearing capacity of a weak clay subgrade can be increased by placing a strong granular base course of limited thickness on top of the clay layer. The load-bearing capacity can be increased further, or the thickness of the granular base course can be reduced, by separating both layers by a geogrid. Laboratory model test results for the ultimate bearing capacity of a rigid strip loading on the surface of a granular soil underlain by a soft clay with a layer of geogrid at the interface of the two soils are presented. The optimum thickness of the granular soil layer and the critical width of the geogrid layer required to derive the maximum benefit from the reinforcement were determined. Model test results on the permanent settlement of the rigid strip load caused by cyclic loading of low frequency are presented.

Bearing capacity of flexible batter piles under eccentric and inclined, loads in layered soil

1994 ◽  
Vol 31 (4) ◽  
pp. 583-590 ◽  
Author(s):  
G.G. Meyerhof ◽  
A.S. Yalcin
Keyword(s):  
Bearing Capacity ◽  
Model Test ◽  
Layered Structure ◽  
Layered Soil ◽  
Head Model ◽  
Test Results ◽  
Inclined Load ◽  
Eccentric Load ◽  
Inclined Loads ◽  
Batter Piles

The behaviour of single free-head model flexible vertical and batter piles under the general case of eccentric and inclined loads in two-layered soil is investigated. The bearing capacity of the piles is found to depend on the layered structure, the eccentricity and inclination of the load, and the pile batter. The theoretical estimates of ultimate loads obtained from semiempirical relations agree fairly well with the test results. Key words : bearing capacity, deformation, batter pile, eccentricity factor, eccentric load, inclination factor, inclined load, layered soil, model test, sand, clay.

scholarly journals Analytical Model for the End-Bearing Capacity of Tapered Piles Using Cavity Expansion Theory

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Suman Manandhar ◽  
Noriyuki Yasufuku
Keyword(s):  
Bearing Capacity ◽  
Cavity Expansion ◽  
Test Results ◽  
End Bearing Capacity ◽  
Proposed Model ◽  
Expansion Theory ◽  
Cavity Expansion Theory ◽  
Bearing Behavior ◽  
Spherical Cavity Expansion ◽  
Real Type

On the basis of evidence from model tests on increasing the end-bearing behavior of tapered piles at the load-settlement curve, this paper proposes an analytical spherical cavity expansion theory to evaluate the end-bearing capacity. The angle of tapering is inserted in the proposed model to evaluate the end-bearing capacity. The test results of the proposed model in different types of sands and different relative densities show good effects compared to conventional straight piles. The end-bearing capacity increases with increases in the tapering angle. The paper then propounds a model for prototypes and real-type pile tests which predicts and validates to evaluate the end-bearing capacity.

Determining Side-by-Side Current Loads Using CFD and Model Tests

2016 ◽  
Author(s):  
Arjen Koop
Keyword(s):  
Reynolds Number ◽  
Model Test ◽  
Full Scale ◽  
Test Results ◽  
Model Scale ◽  
Moment Coefficient ◽  
The Difference ◽  
The Moment ◽  
Good Agreement ◽  
Shielding Effects

When two vessels are positioned close to each other in a current, significant shielding or interaction effects can be observed. In this paper the current loads are determined for a LNG carrier alone, a Shuttle tanker alone and both vessels in side-by-side configuration. The current loads are determined by means of tow tests in a water basin at scale 1:60 and by CFD calculations at model-scale and full-scale Reynolds number. The objective of the measurements was to obtain reference data including shielding effects. CFD calculations at model-scale Reynolds number are carried out and compared with the model test results to determine the capability of CFD to predict the side-by-side current load coefficients. Furthermore, CFD calculations at full-scale Reynolds number are performed to determine the scale effects on current loads. We estimate that the experimental uncertainty ranges between 3% and 5% for the force coefficients CY and CMZ and between 3% and 10% for CX. Based on a grid sensitivity study the numerical sensitivity is estimated to be below 5%. Considering the uncertainties mentioned above, we assume that a good agreement between experiments and CFD calculations is obtained when the difference is within 10%. The best agreement between the model test results and the CFD results for model-scale Reynolds number is obtained for the CY coefficient with differences around 5%. For the CX coefficient the difference can be larger as this coefficient is mainly dominated by the friction component. In the model tests this force is small and therefore difficult to measure. In the CFD calculations the turbulence model used may not be suitable to capture transition from laminar to turbulent flow. A good agreement (around 5% difference) is obtained for the moment coefficient for headings without shielding effects. With shielding effects larger differences can be obtained as for these headings a slight deviation in the wake behind the upstream vessel may result in a large difference for the moment coefficient. Comparing the CFD results at full-scale Reynolds number with the CFD results at model-scale Reynolds number significant differences are found for friction dominated forces. For the CX coefficient a reduction up to 50% can be observed at full-scale Reynolds number. The differences for pressure dominated forces are smaller. For the CY coefficient 5–10% lower values are obtained at full-scale Reynolds number. The moment coefficient CMZ is also dominated by the pressure force, but up to 30% lower values are found at full-scale Reynolds number. The shielding effects appear to be slightly smaller at full-scale Reynolds number as the wake from the upstream vessel is slightly smaller in size resulting in larger forces on the downstream vessel.

Model Test for Fatigue Performance on New Type Solid Round Rigid Suspender for a High-Speed Railway Bridge

2011 ◽  
Vol 368-373 ◽  
pp. 94-99
Author(s):  
Jin Gang Zhao ◽  
Ren Da Zhao ◽  
Yu Lin Zhan
Keyword(s):  
Bearing Capacity ◽  
Model Test ◽  
High Speed ◽  
Stress Amplitude ◽  
Fatigue Performance ◽  
Plastic State ◽  
Test Results ◽  
Railway Bridge ◽  
High Speed Railway ◽  
New Type

This paper presents a study on the fatigue performance of a new type solid round rigid suspender in a high-speed railway bridge. The relevant information about the model design, manufacture, loading procedure and test scheme is presented. The model test results show that the maximum axial stress amplitude are less than the allowable fatigue stress amplitude for most of the measuring points, and no crack occurs on the short and the long suspender models’ body and connection structural detail after 2 million fatigue cycles, the fatigue performance meets the requirement. The bearing capacity test results after fatigue test show that the short and the long suspender models entering plastic state and without fracture under 131% and 119% of the test load. The suspenders’ bearing capacity meets the design requirement. This fatigue model test study shows that the design of the new type solid round rigid suspender is reasonable and safe.

Bearing capacity of foundations on a weak sand layer overlying a strong deposit

1982 ◽  
Vol 19 (3) ◽  
pp. 392-396 ◽  
Author(s):  
A. M. Hanna
Keyword(s):  
Bearing Capacity ◽  
Model Test ◽  
Classical Equation ◽  
Model Tests ◽  
Sand Layer ◽  
Test Results ◽  
Dense Sand ◽  
Design Charts ◽  
Sand Deposit ◽  
Compact Sand

The ultimate bearing capacity of footings resting on subsoils consisting of a weak sand layer overlying a strong deposit has been investigated. Based on model tests of strip and circular footings in a loose or compact sand layer overlying a dense sand deposit, the classical equation of bearing capacity of footings on homogeneous sand was extended to cover cases of these footings in layered sands where the upper layer is the weaker. The theory compared well with the available model test results. Design charts are presented.

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