scholarly journals Installation of Bored Piles with a Protective Silicate Shell of a New Design in Saline Silty-Clayey Soils

2021 ◽  
Vol 11 (15) ◽  
pp. 6935
Author(s):  
Bulat B. Unaibayev ◽  
Bulat Zh. Unaibayev ◽  
Nurgul Alibekova ◽  
Assel Sarsembayeva
Keyword(s):  
Bearing Capacity ◽  
Retaining Wall ◽  
Economic Effect ◽  
Sodium Silicate Solution ◽  
Silicate Solution ◽  
Clayey Soils ◽  
Protective Shell ◽  
Close Relationship ◽  
Load Tests ◽  
Pile Load Tests

Designing advanced methods of corrosion protection and increasing the bearing capacity of pile foundations on saline clayey soils is a priority geotechnical task in Kazakhstan. The formation of a suffusion-resistant waterproof shell was achieved by silicatization of a borehole before concreting, by the installation of a mold into the borehole and the impregnation of a sodium silicate solution into the space between the mold and the soil under pressure. After coagulation of the silicate solution, the mold was removed and the formed shell was filled with corrosion-resistant concrete. Full-scale static pile load tests were conducted in the construction site “Retaining wall on Mount Koktobe” in Almaty. The bearing capacity of the piles with the protective silicate shell exceeded the bearing capacity of an ordinary pile by 2.5 times on average without wetting the site, and 3.2 times after prolonged wetting. The numerical model had a close relationship with the average experimental curve obtained when conducting six static pile load tests with the protective shell. A large economic effect of the developed piling technology with a protective shell was achieved, with a significant reduction in the cost of piling, equal to 27.85%.

scholarly journals Influence of time on the bearing capacity of precast piles

2013 ◽  
Vol 35 (4) ◽  
pp. 65-74 ◽  
Author(s):  
Kazimierz Gwizdała ◽  
Paweł Więcławski
Keyword(s):  
Bearing Capacity ◽  
Cohesive Soils ◽  
Geotechnical Parameters ◽  
Well Control ◽  
Time Points ◽  
Pile Shaft ◽  
Field Investigations ◽  
Load Tests ◽  
Pile Load Tests ◽  
Change Of Microstructure

Abstract One of the most popular types of foundations in layered subsoil with very differentiated soil shear strengths are precast piles. One of the reasons is the fact that we can well control the driving process during the installation of these piles. The principles of the assessment of bearing capacity and settlements of the piles given by Eurocode 7, concentrate on two main methods, i.e., Static Pile Load Tests (SPLT) and Dynamic Driving Analysis (PDA). However, the evaluation of real load-settlement curve for piles being driven in layered subsoil, where noncohesive and cohesive soils occur alternately, is neither easy nor straightforward. In the paper, the results of both SPLT and PDA tests for objects on the highways in Poland are presented. Field investigations carried out at various time points since the installation of piles (from 7 to 90 days) revealed an increase of bearing capacity with time. The reason for this may be a change of the soil state near the piles due to their driving (displacement of piles) as well as a change of microstructure at the contact between soil and pile shaft. The results of load tests were referred to the geotechnical parameters of the subsoil, which was recognized by means of traditional borings and CPTU tests. The results of tests allow phenomena occurring with time to be assessed and bearing capacity of precast piles to be predicted.

scholarly journals Bearing capacity assessment of bored piles equipped with expander body systems using the mechanics of unsaturated soils

2021 ◽  
Vol 337 ◽  
pp. 03011
Author(s):  
Fernando Feitosa Monteiro ◽  
Renato Pinto da Cunha ◽  
Marcos Fábio Porto de Aguiar ◽  
Carlos Medeiros Silva
Keyword(s):  
Bearing Capacity ◽  
Unsaturated Soils ◽  
Federal District ◽  
Matric Suction ◽  
Engineering Practice ◽  
Foundation Engineering ◽  
Load Tests ◽  
Single Piles ◽  
Bored Piles ◽  
Pile Load Tests

Bearing capacity of single piles are occasionally predicted using the renowned theoretical methods (α and β methods). These methods are based on laboratory tests, which can be time-consuming, but also applicable in foundation engineering practice for unsaturated soils. Full-scale pile load tests were carried out on bored piles equipped with Expander Body Systems in the Federal District of Brazil, known for its unsaturated, collapsible and porous soil. This paper has the aim to assess the applicability of the β method, considering the contribution of soil matric suction, in order to estimate the bearing capacity of these piles subjected to uplift and compression loads in unsaturated soils. Based on the experimental results, it is indicated that the use of the β method considering the matric suction, can be a useful tool for bearing capacity estimation of bored piles equipped with Expander Body Systems in unsaturated soils.

Pile load tests in saline permafrost at Clyde River, Northwest Territories

1988 ◽  
Vol 25 (1) ◽  
pp. 24-32 ◽  
Author(s):  
J. F. (Derick) Nixon
Keyword(s):  
Bearing Capacity ◽  
Pore Water ◽  
Salt Content ◽  
Field Testing ◽  
Testing Procedure ◽  
Load Testing ◽  
Pile Design ◽  
Load Tests ◽  
Pore Water Salinity ◽  
Pile Load Tests

Significant salt content in the pore phase of permafrost causes dramatic reduction in strength or bearing capacity. Previous experience with laboratory tests and limited field testing discussed in the Soviet literature indicate that creep rates can be accelerated many times and foundation bearing capacities reduced by factors of 2–3 if pore water salinities exceed 10–20 ppt. At Clyde River on the northwest coast of Baffin Island, pile load tests were carried out in 1982. A combination of high salinities and significant excess ice contents at some locations suggested that a limited program of pile load testing should be carried out to confirm or modify the initial pile loadings based on previously published material. No fully documented case history was available to support initial pile design loads.Three piles were subjected to loads of five different magnitudes for different durations. Creep settlement was initiated and persisted in all cases. Continuous curve fitting was carried out by computer, and the resulting smoothed strain rate plotted with time. The minimum settlement rates were compared with earlier predictions. They were generally somewhat faster than results from previous laboratory saline creep testing combined with theoretical pile design based on creep settlement.The tests highlight the dramatic reductions in foundation bearing capacity and acceleration in pile creep rates that can be expected in permafrost exhibiting significant pore water salinity. A simplified testing procedure suitable for laboratory or field testing is described. Key words: permafrost, saline, piles, load tests, laboratory, field, in situ, capacity, creep, creep rate, salinity test.

Axial compressive capacity of driven piles in sand: a method including post-driving residual stresses

2001 ◽  
Vol 38 (2) ◽  
pp. 364-377
Author(s):  
Ahmed Shlash Alawneh ◽  
Osama Nusier ◽  
Abdullah I Husein Malkawi ◽  
Mustafa Al-Kateeb
Keyword(s):  
Residual Stresses ◽  
Bearing Capacity ◽  
Relative Density ◽  
Friction Angle ◽  
Accurate Estimate ◽  
Driven Piles ◽  
Pile Capacity ◽  
Shaft Resistance ◽  
Load Tests ◽  
Pile Load Tests

In this paper, empirical formulae were developed between the well-known pile bearing capacity factors (Nq and β) and parameters which include friction angle of sand, relative density, average effective vertical stress, and deformability of the soil below the pile toe. The developed empirical formulae were totally based on a database comprised of 28 well-documented compressive pile load tests collected exclusively from geotechnical literature. The actual measurements of shaft and end-bearing resistances of each pile in the database were adjusted to account for post-driving residual loads. Calculation of pile bearing capacity factors (Nq and β) was based on the adjusted shaft and end-bearing resistances rather than the actual unadjusted measured resistances for residual loads. Comparison of predicted and measured compressive capacity of an independent database comprised of 18 pile load tests showed that the developed formulae yield a reasonably accurate estimate of compressive pile capacity in cohesionless soils.Key words: driven piles, residual load, toe resistance, shaft resistance.

scholarly journals Accuracy of pile capacity assessment on the basis of piling reports

2019 ◽  
Vol 97 ◽  
pp. 04029 ◽  
Author(s):  
Jakub Rainer
Keyword(s):  
Bearing Capacity ◽  
Operational Reliability ◽  
Driven Piles ◽  
Safety Factors ◽  
Pile Capacity ◽  
Current Assessment ◽  
Proper Design ◽  
Foundation Pile ◽  
Load Tests ◽  
Pile Load Tests

Current assessment of foundation pile bearing capacity during driving may considerably improve operational reliability in terms of loads to be transferred. It also enables proper design and trial examinations by focusing attention on piles with atypical driving characteristics. The paper presents the method applicable to assess the bearing capacity of prefabricated driven piles and provides analysis of likelihood of this assessment by the example of numerous prefabricated piles documented by piling reports and results of static pile load tests to the extent allowing to determining the limit bearing capacity. The results attained could be the basis to determine respective safety factors in pile design based on driving resistance analysis.

scholarly journals The Ultimate Pile Bearing Capacity from Conventional and Spectral Analysis of Surface Wave (SASW) Measurements

2018 ◽  
Vol 34 ◽  
pp. 01031
Author(s):  
Nor Faizah Bawadi ◽  
Shamilah Anuar ◽  
Mustaqqim A.Rahim ◽  
A.Faizal Mansor
Keyword(s):  
Spectral Analysis ◽  
Surface Wave ◽  
Bearing Capacity ◽  
Back Analysis ◽  
Seismic Method ◽  
Response Data ◽  
Methods Of Evaluation ◽  
Load Tests ◽  
Conventional Methods ◽  
Pile Load Tests

A conventional and seismic method for determining the ultimate pile bearing capacity was proposed and compared. The Spectral Analysis of Surface Wave (SASW) method is one of the non-destructive seismic techniques that do not require drilling and sampling of soils, was used in the determination of shear wave velocity (Vs) and damping (D) profile of soil. The soil strength was found to be directly proportional to the Vs and its value has been successfully applied to obtain shallow bearing capacity empirically. A method is proposed in this study to determine the pile bearing capacity using Vs and D measurements for the design of pile and also as an alternative method to verify the bearing capacity from the other conventional methods of evaluation. The objectives of this study are to determine Vs and D profile through frequency response data from SASW measurements and to compare pile bearing capacities obtained from the method carried out and conventional methods. All SASW test arrays were conducted near the borehole and location of conventional pile load tests. In obtaining skin and end bearing pile resistance, the Hardin and Drnevich equation has been used with reference strains obtained from the method proposed by Abbiss. Back analysis results of pile bearing capacities from SASW were found to be 18981 kN and 4947 kN compared to 18014 kN and 4633 kN of IPLT with differences of 5% and 6% for Damansara and Kuala Lumpur test sites, respectively. The results of this study indicate that the seismic method proposed in this study has the potential to be used in estimating the pile bearing capacity.

scholarly journals The Results of Dynamic (Pile Driving Analysis) and Traditional Static Piling Tests in Capital of Kazakhstan

2016 ◽  
Author(s):  
Askar Zhussupbekov ◽  
Rauan Lukpanov ◽  
Abdulla Omarov
Keyword(s):  
Bearing Capacity ◽  
Test Methods ◽  
Load Test ◽  
Construction Site ◽  
Depth Of Penetration ◽  
Railway Station ◽  
Static Tests ◽  
Load Tests ◽  
Pile Load Test ◽  
Pile Load Tests

Traditionally, pile load tests in Kazakhstan are carried out using static and dynamic load test methods. Static pile load test is the most reliable method to obtain the load-settlement relation of piles. Most of the static pile load tests are performed using reaction systems. Furthermore, cost and time for the static pile load test are relatively high compared to the dynamic pile load testing. Therefore, the number of pile load tests in construction site is limited to 2 or 5 piles in usual of constructed piles In Kazakhstan. This paper includes the short summary about dynamic and static tests by driven piles (cross-section 30×30 cm and length of 12 m). The methodologies of definition bearing capacity of the pile by aforementioned methods were also given. As an example for those methods, paper describes the results of the dynamic, traditional static and the new PDA (Pile Dynamic Analyzer) tests of cooperative work of soils and piles performed in the construction site of the New Railway Station in Astana. According to the results of tests were determined the possible depth of penetration and bearing capacity of piles, as well as recommendations on the device of working. The construction is part of the preparations for EXPO 2017. It will be 11 times bigger than the existing railway station. The height of the six-floor complex will be 49.5 metres, the width 116 metres and the length 630 metres.

scholarly journals Printability and Setting Time of CSA Cement with Na2SiO3 and Gypsum for Binder Jetting 3D Printing

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2811
Author(s):  
Okpin Na ◽  
Kangmin Kim ◽  
Hyunjoo Lee ◽  
Hyunseung Lee
Keyword(s):  
3D Printing ◽  
Sodium Silicate ◽  
Setting Time ◽  
Sodium Silicate Solution ◽  
Preliminary Test ◽  
Silicate Solution ◽  
Calcium Sulfoaluminate Cement ◽  
Calcium Sulfoaluminate ◽  
Parametric Studies ◽  
Binder Jetting

The purpose of this study is to optimize the composition of CSA (calcium sulfoaluminate) cement with sodium silicate (Na2SiO3) and gypsum for binder jetting 3D printing. The preliminary test was carried out with an applicator to decide the proper thickness of one layer before using the 3D printer. A liquid binder was then selected to maintain the shape of the particles. Based on the results, the optimal mixture of dry materials and a liquid activator was derived through various parametric studies. For dry materials, the optimum composition of CSA cement, gypsum, and sand was suggested, and the liquid activator made with sodium silicate solution and VMA (viscosity modified agent) were selected. The setting time with gypsum and sodium silicate was controlled within 30 s. In case of the delayed setting time and the rapid setting mixture, the jetting line was printed thicker or thinner and the accuracy of the printout was degraded. In order to adjust the viscosity of the liquid activator, 10% of the VMA was used in 35% of sodium silicate solution and the viscosity of 200–400 cP was suitable to be sprayed from the nozzle. With this optimal mixture, a prototype of atypical decorative wall was printed, and the compressive strength was measured at about 7 MPa.

scholarly journals Silica extraction from bauxite reaction residue and synthesis water glass

2021 ◽  
Vol 10 (1) ◽  
pp. 268-283
Author(s):  
Yunlong Zhao ◽  
Yajie Zheng ◽  
Hanbing He ◽  
Zhaoming Sun ◽  
An Li
Keyword(s):  
Sodium Silicate ◽  
Water Glass ◽  
Sodium Silicate Solution ◽  
Silicate Solution ◽  
Hydrated Calcium Silicate ◽  
Precipitated Silica ◽  
Alumina Gel ◽  
Silica Alumina ◽  
Element Removal ◽  
Hydrated Calcium

Abstract Bauxite reaction residue (BRR) produced from the poly-aluminum chloride (PAC) coagulant industry is a solid acidic waste that is harmful to environment. A low temperature synthesis route to convert the waste into water glass was reported. Silica dissolution process was systematically studied, including the thermodynamic analysis and the influence of calcium and aluminum on the leaching of amorphous silica. Simulation studies have shown that calcium and aluminum combine with silicon to form hydrated calcium silicate, silica–alumina gel, and zeolite, respectively, thereby hindering the leaching of silica. Maximizing the removal of calcium, aluminum, and chlorine can effectively improve the leaching of silicon in the subsequent process, and corresponding element removal rates are 42.81%, 44.15%, and 96.94%, respectively. The removed material is not randomly discarded and is reused to prepare PAC. The silica extraction rate reached 81.45% under optimal conditions (NaOH; 3 mol L−1, L S−1; 5/1, 75°C, 2 h), and sodium silicate modulus (nSiO2:nNa2O) is 1.11. The results indicated that a large amount of silica was existed in amorphous form. Precipitated silica was obtained by acidifying sodium silicate solution at optimal pH 7.0. Moreover, sodium silicate (1.11) further synthesizes sodium silicate (modulus 3.27) by adding precipitated silica at 75°C.

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