BEARING CAPACITY OF CAST-IN-PLACE PILES ON THE BASIS OF IN SITU STATIC LOAD TESTS

2011 ◽  
Author(s):  
Vladimir Kostov
Keyword(s):  
Bearing Capacity ◽  
Static Load ◽  
Load Tests

scholarly journals Bi-Directional Static Load Tests of Pile Models

2020 ◽  
Vol 10 (16) ◽  
pp. 5492
Author(s):  
Michał Baca ◽  
Włodzimierz Brząkała ◽  
Jarosław Rybak
Keyword(s):  
Bearing Capacity ◽  
Static Load ◽  
Load Testing ◽  
Pile Capacity ◽  
Pile Shaft ◽  
Load Tests ◽  
S Curve ◽  
Definition Of ◽  
Standard Tests ◽  
Static Load Testing

This work examined a new method of bi-directional static load testing for piles, referencing the Osterberg test. Measurements were taken, on a laboratory scale, using six models of piles driven into a box filled with sand. This method allowed for separate measurements of pile base and pile shaft bearing capacities. Based on the results, the total pile bearing capacity and equivalent Q–s diagrams were estimated. The results obtained show that the structure of the equivalent curve according to Osterberg is a good approximation of the standard Q–s curve obtained from load tests, except for loads close to the limit of bearing capacity (those estimates are also complicated by the inapplicability and ambiguity of a definition of the notion of limit bearing capacity); the equivalent pile capacity in the Osterberg method represents, on average, about 80% of the capacity from standard tests.

scholarly journals Static Load Tests, Short Series Interpretation

2015 ◽  
Vol 36 (2) ◽  
pp. 45-49 ◽  
Author(s):  
Zygmunt Meyer
Keyword(s):  
Critical Load ◽  
Bearing Capacity ◽  
Static Load ◽  
Critical Value ◽  
Load Test ◽  
Practical Calculation ◽  
Short Series ◽  
Load Tests ◽  
S Curve

Abstract Statistic load test is the most commonly used method for estimation of the bearing capacity of piles. From the test we obtain the series a values: load-settlement, Q–s curve. In practice, it is extremely difficult to reach the critical load of the pile when the settlement turns out of control. The existing methods that allow bearing capacity to be calculated give the value which is very often 1/10 of the critical load. The question arises if it is possible based upon short series of load, i.e., 0–0.4 critical load, to predict the critical value of the load, with accuracy which is sufficient for practical calculation. The paper presents a method how to calculate the critical load based upon short series of load in the static load tests.

scholarly journals EFFECT OF DIFFERENT WOOD DOWELS ON MECHANICAL PROPERTIES OF TRIANGULAR GIRDER TRUSSES

Wood Research ◽  
2021 ◽  
Vol 66 (3) ◽  
pp. 477-488
Author(s):  
Liuliu Zhang ◽  
Cheng Chang ◽  
Shuming Yang
Keyword(s):  
Mechanical Properties ◽  
Energy Dissipation ◽  
Bearing Capacity ◽  
Static Load ◽  
Deformation Resistance ◽  
Stability Performance ◽  
Load Tests ◽  
Different Diameters

Static load tests were carried out on three kinds of triangular girder trusses with different diameter wood dowels, and the effects of that on the structure of girder trusses were discussed. It was found that there was a good synergy between the wood dowels and the girder trusses. Among the triangular girder trusses with different diameters, the 16 mm diameters had the best energy dissipation performance increased by 184% and deformation resistance of 0.73 mm; the 20 mm diameters had the best stability performance, the better bearing capacity of 60.42 kN and deformation resistance of 0.82 mm. The bearing capacity of the double girder trusses was 2.06-2.25 times that of two single trusses, which had the ability to ‘one plus one is greater than two’.

scholarly journals Study on the Bearing Capacity and Engineering Performance of Aeolian Sand

2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Han Xia ◽  
Jingtao Zhang ◽  
Jun Cai ◽  
Huangsong Pan ◽  
Xuesen She
Keyword(s):  
Bearing Capacity ◽  
Soil Structure ◽  
Soil Layer ◽  
Aeolian Sand ◽  
Mu Us Desert ◽  
Large Numbers ◽  
Loose Soil ◽  
Load Tests ◽  
Physical And Mechanical Characteristics

The climate in the aeolian desert has great differences from that in other regions, generally showing large diurnal temperature differences and extremely dry and low groundwater level characteristics. Therefore, the physical and mechanical characteristics of the sand are different from those of other regions, and it has a loose soil structure, large pores, and a low bearing capacity. To ensure the security and applicability of engineering, it is necessary to study the engineering characteristics of aeolian sand. This paper focuses on the bearing capacity parameters of aeolian sand in the Mu Us Desert, and test sites in 6 weak foundation areas are selected. Large numbers of basic soil mechanical parameters have been collected through in situ static load tests (SLT) and laboratory confined compaction tests (CCT) to evaluate the effect of foundation treatments. The results show that the characteristics of aeolian sand in the Mu Us Desert include low moisture, poor cohesion, and easy compaction. The mud and water content affect the bearing capacity of aeolian sand. For weak foundations, adding a geogrid or replacing a weak soil layer with stone and aeolian sand can significantly improve the bearing capacity.

scholarly journals Predicting the bearing capacity of pile installed into cohesive soil concerning the spatial variability of SPT data (A case study)

2021 ◽  
Vol 11 (1) ◽  
pp. 45-64
Author(s):  
Duong Hong Tham ◽  
Truong Nhu Manh
Keyword(s):  
Bearing Capacity ◽  
Static Load ◽  
Physical And Mechanical Properties ◽  
Cohesive Soil ◽  
Load Test ◽  
Penetration Test ◽  
Static Load Test ◽  
In Situ Tests ◽  
Spt Data

Nowadays, in situ tests have played a viable role in geotechnical engineering and construction technology. Besides lab tests conducted on undisturbed soil samples, many different kinds of in-situ tests were used and proved to be more efficient in foundation design such as pressuremeter PMT, cone penetration test CPT, standard SPT, etc. Among them, a standard penetration test (SPT for short) is easy to carry out at the site. For decades, it has proved reliable to sandy soil, but many viewpoints and opinions argued that the test was not appropriately applicable to cohesive soil because of scattered and dispersed data of SPT blow counts through different layers. This paper firstly studies how reliable the SPT data can predict the physical and mechanical properties; secondly, the soil strength is determined in terms of corrected N-SPT values, and finally the bearing capacity of a pile penetrating cohesion soil. By analyzing data from 40 boreholes located in 18 projects in Ho Chi Minh City, South VietNam, coefficients of determination between SPT numbers and physical and mechanical properties of different soil kinds are not the same: R2 = 0.623 for sand, =0.363 for sandy clay and =0.189 for clay. The spatial variability of soil properties is taken into account by calculating the scale of fluctuation θ=4.65m beside the statistically-based data in horizontal directions. Finally, the results from two theoretical approaches of predicting pile bearing capacity were compared to those of finite element program Plaxis 3D and static load test at site. Correlation between the capacity computed by using corrected N-values instead of soil strength and results of static load test has proved to be well suitable in evaluating the bearing capacity of driven and jack-in piles, particularly installing in the cohesive soil using the SPT blows.

EXPERIMENTAL EVALUATION OF SOIL REINFORCEMENTS IN UNPAVED ROAD

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Nahla Salim
Keyword(s):  
Bearing Capacity ◽  
Static Load ◽  
Sandy Soils ◽  
Crushed Stone ◽  
Unit Weight ◽  
Harmonic Load ◽  
Geogrid Reinforcement ◽  
Dry Unit Weight ◽  
Load Tests ◽  
Number Of Cycles

In this study, a series of 24 laboratory tests were conducted on a footing resting on crushed stone with 17.68 kN/m3 dry unit weight overlying sandy soils of two relative densities corresponding to (60% and 80%). The subbase layer is of crushed stone with a thickness of 5, 7.5 and 10 cm. Ten tests were conducted under static load with and without geogrid. All the other 14 model tests were carried out under harmonic load which was applied in a sequence determined prior (40% of static load). Tests were conducted at (2) Hz frequency according to the loading value. The process of the loading was continued until the number of cycles reached 104. The results indicated that, for static load and with the inclusion of the geogrid, as the thickness of the subbase layer increases, the percentage of increase in bearing capacity was reduced. In general, using geogrid reinforcement with subbase thickness of 7.5 and 5 cm causes an increase in bearing capacity approximately 1.5 to 2 times greater than for unreinforced respectively. This means that by using geogrid reinforcement, the thickness of subbase can be reduced which causes a reduction in construction cost.

scholarly journals Analysis of the Bearing Capacity of Helical Pile with Hexagonal Joints

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1890 ◽  
Author(s):  
Daehyeon Kim ◽  
Kyemoon Baek ◽  
Kyungho Park
Keyword(s):  
Bearing Capacity ◽  
Field Test ◽  
Static Load ◽  
Load Test ◽  
Basic Data ◽  
Pile Installation ◽  
Helical Piles ◽  
Load Tests ◽  
Pile Load Test

This study aims to improve shafts with hexagonal joints so that they will not require welding or bolts in static load tests. In order to evaluate the bearing capacity of helical piles, two sites were selected to conduct pile installation for the field test and the pile load test. For the pile load test, a static pile load test and a dynamic pile load test were carried out, and torque was measured during pile installation in a field test to compare and analyze the expected bearing capacity and thus assess the feasibility of the method for estimating the bearing capacity. The field pile load test revealed that the bearing capacity of the gravity grout pile was the same or greater than 600 kN in the static pile load test in accordance with the AC 358 code. The non-grout pile showed a bearing capacity that was the same or smaller than 600 kN, suggesting that gravity grouting is required. Moreover, the field pile load test was used to establish the bearing capacity equation considering the torque in the pile installation, and a small number of samples were used to establish the equation, which can be used as basic data.

scholarly journals Application of the ‘CPT 2012’ model of AFNOR standard for column design in Poland – Jazowa case study

2019 ◽  
Vol 262 ◽  
pp. 04001
Author(s):  
Lech Bałachowski ◽  
Jakub Konkol ◽  
Kamila Międlarz
Keyword(s):  
Bearing Capacity ◽  
Static Load ◽  
Eurocode 7 ◽  
Pile Design ◽  
Load Tests ◽  
Column Design ◽  
French Standard

This paper presents the ‘CPT 2012’ model incorporated into the AFNOR NF P94-262:2012-07, French standard for pile design fully compatible with Eurocode 7, to the wider Polish audience. The bearing capacity of three reference columns for Vistula Marshlands have been calculated according to ‘CPT 2012’ model and AFNOR recommendations. Then, the design resistances have been compared with ultimate column bearing capacity measured during static load tests conducted on reference columns. The results of comparison are discussed and the discrepancies between measured and calculated bearing capacities are shortly commented.

Reliability Analysis of Vertical Bearing Capacity of Pile Based on Static Load Tests

2011 ◽  
Vol 243-249 ◽  
pp. 5745-5750
Author(s):  
Shi Qing Liu ◽  
Jun Jie Zheng ◽  
Zhi Jun Xu ◽  
Xiao Ya Bian
Keyword(s):  
Bearing Capacity ◽  
Static Load ◽  
Design Parameters ◽  
Building Foundation ◽  
Range Theory ◽  
Load Tests ◽  
Sample Range ◽  
Single Piles ◽  
Vertical Bearing ◽  
Vertical Bearing Capacity

Based on the sample range theory in Mathematical Statistics, the general standard variance of vertical capacity of single piles is evaluated according to the data from static load tests, and a method is presented to evaluate the reliability of vertical bearing capacity of pile, of which distribution obeys normal distribution. Finally, results from the case study indicate that it is effective to evaluate the reliability using the method presented in this paper, and the number of tested piles specified in Technical Code for Testing of Building Foundation piles and determining sample range can be interpreted reasonably in theory. Meanwhile, it can give good references to designers to determine the design parameters according to testing piles.

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