Standard Penetration Test Results Research Articles

Determine attenuation coefficients of saturated sand from standard penetration test, applied to Nhon Hoi economic zone

Vietnam is located in a strong earthquake zone with many areas having a ground acceleration (a<sub>g</sub>) of greater than 0.08 g (TCVN 9386:2012). According to Vietnamese standard TCVN 9386:2012, the calculation and design of construction grade III or higher in areas where have ground acceleration a<sub>g</sub> ≥ 0.08 g must include seismic design. In calculations of earthquake-resistant pile foundation, the bearing capacity of the pile including the tip resistance strength (q<sub>b</sub>) and endurance strength (f<sub>i</sub>) need to be multiplied by attenuation coefficients (g<sub>eq1</sub> and g<sub>eq2</sub>). They are the most important parameters and depend on the soil types, saturation conditions, and earthquake intensity. The article introduces a method to determine the attenuation coefficients according to the standard TCVN 10304:2014. In addition, analyzing the theoretical basis to give the expression to determine attenuation coefficients based on the durability factor (I<sub>red</sub>) and pore water pressure ratio (R<sub>u</sub>) of saturated sand under the earthquakes. Furthermore, the paper presents a method to determine R<sub>u</sub> from the results of standard penetration test (SPT) by combining the method of Seed and Alba (1986) with the method of Marcuson and Hynes (1990). In which, Seed and Alba's method was used to determine factor of safety against liquefaction (F<sub>SL</sub>), and then Marcuson and Hynes' method was used to determine R<sub>u</sub> from F<sub>SL</sub>. The application in Nhon Hoi Economic Zone shows that: The silty fine grained sand, which is medium dense and saturated, has a attenuation coefficient of tip resistance g<sub>eq1</sub> = 0.74÷0.76 and attenuation coefficient of friction g<sub>eq2</sub> = 0.90; The fine grained sand, which is dense and saturated, has g<sub>eq1</sub> = 0.79÷0.82 and g<sub>eq2</sub> = 0.94. 

Soil nailing as a ground reinforcement method of a storey building constructed on weathered siltstone: Analytical and numerical evaluation

Vietnam is located in a strong earthquake zone with many areas having a ground acceleration (a<sub>g</sub>) of greater than 0.08 g (TCVN 9386:2012). According to Vietnamese standard TCVN 9386:2012, the calculation and design of construction grade III or higher in areas where have ground acceleration a<sub>g</sub> ≥ 0.08 g must include seismic design. In calculations of earthquake-resistant pile foundation, the bearing capacity of the pile including the tip resistance strength (q<sub>b</sub>) and endurance strength (f<sub>i</sub>) need to be multiplied by attenuation coefficients (g<sub>eq1</sub> and g<sub>eq2</sub>). They are the most important parameters and depend on the soil types, saturation conditions, and earthquake intensity. The article introduces a method to determine the attenuation coefficients according to the standard TCVN 10304:2014. In addition, analyzing the theoretical basis to give the expression to determine attenuation coefficients based on the durability factor (I<sub>red</sub>) and pore water pressure ratio (R<sub>u</sub>) of saturated sand under the earthquakes. Furthermore, the paper presents a method to determine R<sub>u</sub> from the results of standard penetration test (SPT) by combining the method of Seed and Alba (1986) with the method of Marcuson and Hynes (1990). In which, Seed and Alba's method was used to determine factor of safety against liquefaction (F<sub>SL</sub>), and then Marcuson and Hynes' method was used to determine R<sub>u</sub> from F<sub>SL</sub>. The application in Nhon Hoi Economic Zone shows that: The silty fine grained sand, which is medium dense and saturated, has a attenuation coefficient of tip resistance g<sub>eq1</sub> = 0.74÷0.76 and attenuation coefficient of friction g<sub>eq2</sub> = 0.90; The fine grained sand, which is dense and saturated, has g<sub>eq1</sub> = 0.79÷0.82 and g<sub>eq2</sub> = 0.94. 

Standard Penetration Test in Malaysia: Safety Issues and Improvement Opportunities

Standard Penetration Test (SPT) is the most frequently used field test for site investigation where drilling work is performed in-situ to determine properties of geomaterials for a project. The SPT results can be affected by the ‘SPT System,’ which includes the operator of the drill rig, the specific model of the drill rig itself, the SPT equipment used to perform the test, and the procedures used in performing the overall test. The safety hazards associated with the system affect the SPT results. Although several countries are embracing innovative technologies in the SPT drilling works to enhance safety performance, the adoption of these technologies in Malaysia remains relatively sluggish. This study aims to analyse the current SPT practice in Malaysia from the lens of ‘the SPT System,’ technologies used in the SPT drilling works, and identify the best practice adopted locally in ensuring safety. This study collected 102 responses using a questionnaire survey validated by four construction professionals experienced in the SPT drilling works. The study revealed that the British Standards are the most used standards in Malaysia. The traditional methods are still being practiced as the “SPT System’ in Malaysia due to the difficulties in obtaining skilled operators for new technology adoption. Advanced technologies have not been adopted because construction professionals are complacent with the current technologies. Amongst innovative safety gear, smart equipment tags and smart wrist wearables are the most favourable. This study presents new findings and sheds light into the local practice of the construction professionals in Malaysia in the SPT drilling works. This study provides an insight for Malaysian construction industry to develop a strategy in improving the efficiency and safety of SPT drilling works through adoption of innovative technologies. Technology driven safety hazard mitigation may boost Malaysian Technical and Vocational Education and Training (TVET) industry and in doing so will increase TVET operators to be trained and certified.

Geotechnical Properties of Soils in Abu Al-Khasib City, Southern Iraq

To investigate some geotechnical characteristics of the soils in a chosen area of Abu Al-Khasib city, Basrah Governorate, southern Iraq, nine boreholes that range in depth from 10 to 32 meters were drilled. Based on the results of standard penetration tests and particle size analysis the Quaternary deposits, which extend vertically to a depth of 32 meters, are divided into 8 layers with varying bearing capacities depending on their consistency and compactness. These layers are Medium stiff brown lean clay, soft and very soft gray lean clay, medium stiff gray lean clay, stiff gray lean clay, medium denes gray silty sand, denes gray silty sand , hard gray clay-silt-sand mixture and very dense gray silty sand. The first layer's bearing capacity is 140 kN/m2, so it is considered as moderately adequate to support the isolated, strip,or raft shallow foundations of various light buildings in the study region, and soil improvement techniques, especially mechanical methods, are required. Different types of deep foundations such as piles and well foundations for heavy constructions must be extended to depths of 27 and 30 meters, which represents the 7th and 8th layers of high bearing capacity (640-760, 1100 kN/m2 respectively) in the study area. Inorganic clays with low plasticity are the most common classification for samples. The soils of the study area are considered highly compressible soils and have medium expansion degree which must be taken into account when constructing shallow foundations to minimize damage to buildings. The percentages of sulphates, total dissolved salts, organic content, and gypsum content are minimal and considered ineffective, whereas the percentages of carbonates and chlorides are high and affect the safety of shallow foundations. In the study site, the groundwater is around 0.5 m deep.

A correlation based on pressuremeter, SPT and CPT tests for characterizing of coastal alluvium: A study for phase 14 South Pars, Iran

Pressuremeter Test (PMT), Cone Penetration Test (CPT), and Standard Penetration Test (SPT) are the key in-situ experiments to directly estimate the in-situ modulus of deformation and strength parameters of soils, which are highly used in coastal alluvium. In addition, CPT and SPT are unique tests for estimating engineering properties that are ideal for onshore regions. These tests are adaptable for coastal alluvium with different saturation levels, which facilitates the determination of the field deformation modulus. Regression analysis, on the other hand, is primarily employed to estimate the empirical relationship between measured parameters and to predict geo-engineering properties. This technique is typically used to estimate the in-situ modulus of deformation and strength parameters from CPT, SPT, and PMT results. The proposed formulas in this paper used regression to correlate and characterize coastal alluvium located in phase 14 South Pars (Assalouyeh) and were compared with previously published equations. As a result of the evaluations, the correlations provided for phase 14 South Pars can be expressed as Em = 0.442 qc + 2.221 (R2 = 0.999) and PL = 0.06 Em0.778 (R2 = 0.515).•This empirical method can be useful for ground assessment and estimating the in-situ modulus of deformation.•This relationship can use as a modification for the original formula used based on CPT-PMT-SPT for alluvium.•This empirical correlation provides fast and reliable data for Southwest Iran nearby the Persian Gulf.

Comparison of Individual Bored Pile Bearing Capacity Using the Results of Standard Penetration Test (SPT) and Pile Driving Analysis (PDA) Test of the Railway Bridge Foundation

Prediction of the bearing capacity of deep foundations using analytical methods from the results of the standard Penetration Test has been carried out until now due to practical consideration. However, with the many types of empirical formulas proposed by various researchers, it is necessary to test the validity of the values predicted by the empirical formulas. During the construction stage, the bearing capacity of deep foundations can be checked using the Pile Driving Analysis (PDA) Test. This study aimed to compare the foundation bearing capacity prediction results using analytical methods of Luciano Decourt (1982), Reese and O'Neil (1999), and Building Standard Law of Japan with the results from PDA test. The comparison indicate that the analytical method of Luciano Decourt (1982) predict bearing capacity with the smallest error rate, which is 1.97% to 38.99% with safaty factor (SF) 2 to 3 on a relatively homogeneous and heterogeneous soil conditions. Prediction of bearing capacity of bored pile foundations using analytical methods O'Neil & Reese (1999) and Building Standard Law of Japan provide better performance for soil types which is dominated by cohesive soils with safety factor (SF) 2.

Lateral response evaluation of single piles based on pressuremeter test results (using Foxta) versus standard penetration test results (using Lpile)

Lateral response evaluation of single piles based on pressuremeter test results (using Foxta) versus standard penetration test results (using Lpile)

Influence of Drilling Methods on the Results of Standard Penetration Test in Loess–Paleosol Sequence

Standard penetration test (SPT) is an important in situ measurement for field investigation of geotechnical and geological engineering. The drilling approaches for implementation of SPT can be classified into dry, wet, and water circulation drillings according to the amount of water used during drilling process. However, the influences of these drilling methods on the SPT results remain unclear, especially when being used in loess–paleosol sequence that is water sensitive. In this study, SPT tests were conducted in a typical loess stratum in the Loess Plateau of China. The difference of SPT N values under the above three drilling methods was compared together with the analysis of characteristics of samples from SPT sampler. The results showed that the N value exhibits positive correlation with dry density of the soil and negative correlation with moisture content. In shallow soil, the average N value under water circulation drilling was slightly higher than that of dry and wet drilling. This is because that the residual soil at the bottom of the drillhole caused by water circulation drilling provides additional penetration resistance. In deep soil, the difference of average N values among all three drilling methods was minimal although the structure of the samples from the SPT sampler differs from one another, indicating the determination of soil density on the SPT result. Empirical equations were proposed for the estimation of unconfined compressive strength of loess–paleosol sequence on the basis of SPT N values under the three drilling methods. Considering the efficiency of drilling and stability of SPT results, it is suggested that wet drilling is the most applicable method for implementation of SPT in the field investigation of loess–paleosol sequence.

Prediction of bearing capacity of driven piles for Basrah governatore using SPT and MATLAB

Abstract Based on the results of standard penetration tests (SPTs) conducted in Al-Basrah governorate, this research aims to present thematic maps and equations for estimating the bearing capacity of driven piles having several lengths. The work includes drilling 135 boreholes to a depth of 10 m below the existing ground level and three standard penetration tests (SPT) at depths of 1.5, 6, and 9.5 m were conducted in each borehole. MATLAB software and corrected SPT values were used to determine the bearing capacity of driven piles in Al-Basrah. Several-order interpolation polynomials are suggested to estimate the bearing capacity of driven piles, but the first-order polynomial is considered the most straightforward. Furthermore, the root means squared error (RMSE) for all suggested polynomials are roughly the same. The production of thematic maps demonstrates the variation in bearing capacity of driven piles over the entire territory of Al-Basrah governorate in correlation with different depths. The results of the statistical equations showed that there is good agreement with those obtained from the SPT data. When compared with the observed values from SPT, the allowable bearing capacity results for the driven piles ranged from (−3 to +38)%. The main results of this study showed a variation of 30% between calculated and estimated values of bearing capacity of driven piles for all lengths of piles at a 95% confidence interval.

Quality Assessment of Dry Soil Mixing Columns in Soft Soil Areas of Eastern China

To investigate the quality of dry soil mixing (DSM) columns in different soft soil areas of east China, a large number of laboratory test results and field test results of DSM columns were collected and analyzed statistically. Furthermore, a quality assessment method for DSM columns is proposed in this paper. The hardness description (HD), standard penetration test (SPT), unconfined compressive strength (UCS), and soil-cement column quality designation (SCQD) are used as assessment indexes. The statistical analysis showed that the test results of SPT, UCS, and SCQD were scattered, particularly in shallow ground. The mean values of the SPT blow count, UCS, and SCQD of the DSM columns decreased with depth: the greater the depth, the worse the quality of DSM columns. The quality assessment results showed that the proportion of the great quality columns was 64.84%, and the proportion of the unqualified columns was 1.4%. The proportion of DSM columns with great quality in the lagoon soft soil area was greater than in other areas. The proportion of unqualified columns in the lacustrine soft soil area was the largest. For all soft soil areas, the proportions of great quality, good quality, general quality, and unqualified soil decreased in that order. The quality assessment of 8627 DSM columns showed the proportions of great quality and unqualified were 64.84% and 1.4%, respectively. It was found that the greater the depth of the DSM column, the more unqualified DSM columns, and the more difficult it was to control the quality of DSM columns.

Investigation into Effect of Sonic Drilling Methodology on Standard Penetration Test Results in Dense Sand

Abstract An extensive field investigation was conducted to quantify the variation between drilling methodologies on the SPT outputs (SPT-N60 values) in dense saturated sands. For this experiment, a test site with reasonably consistent soil properties was identified, where multiple standard penetration tests (SPTs) were conducted using four drilling methodologies, including rotary core, direct push, and two sonic drilling methods. Considering the rotary core as the benchmark, the SPT-N values obtained from this method were systematically compared with those from the other three drilling methodologies. For the dense saturated sands studied in this research, the SPT-N values from rotary sonic DT-45 showed the closest correlation to the SPT-N values from the rotary core, with about 15% variation. The variation was shown not to be statistically significant, considering the inherent variability of the SPT and the measured confidence interval of the SPT-N values from the standard rotary core method.

Voxel modeling of geotechnical characteristics in an urban area by natural neighbor interpolation using a large number of borehole logs

Borehole logs are important geospatial data for understanding subsurface geological and geotechnical conditions. Recently, many borehole logs in urban areas have been open to the public on the Internet in machine-readable file format. However, a few simple methods allow us to construct a voxel model of geological and geotechnical characteristics with high objectivity of the modeling process. Our work aims to develop a simple method that facilitates the use of open borehole logs in geological and geotechnical investigations in urban areas. In this paper, we propose a voxel modeling method of geotechnical data using the machine-readable open borehole logs. The method is designed to construct voxel models of lithofacies and standard penetration test results by stacking a series of horizontal two-dimensional grid data that are created by natural neighbor interpolation using geotechnical data stored in borehole logs at regular elevation intervals. A test calculation to evaluate the proposed method was performed using a large number of borehole logs in the Tokyo metropolitan area, Japan. Results confirmed that the proposed method not only allows us to ensure the objectivity of the modeling process but also provides a good overview of the three-dimensional distribution pattern of the subsurface geotechnical characteristics without any setting of complicated calculation parameters. In conclusion, the proposed method improves the efficiency of geological analyses, such as stratigraphic correlation using borehole logs, and facilitates the use of open borehole logs in urban areas.

Analysis Of Geoelectrical And Soil Test Data To Determine Subsurface Conditions In Makassar City, South Sulawesi

Research has been carried out to determine subsurface conditions. The research objective was to determine the physical properties of the soil in order to evaluate and provide recommendations for solving foundation problems. The methods are the resistivity geoelectric and IP geoelectric method (induced polarization) with ERT (Electrical Resistivity Tomography), SPT (Standard Penetration Test) and laboratory test results. The results of the resistivity values obtained varied in the range from 17.0 - 172.0 ohm m with a depth of 0 m - 2.87 m, most of which were interpreted as alluvium soil, namely sandy loam. This is reinforced by the results of the IP method where the low chargebility value is around 0.130 - 4.70 msec. In addition, it was found that from the SPT test, it was obtained that the variation of blows from 14 to 21 N at a depth of 0 - 5.50 meters and >60 N from a depth of 5.50 - 20 m which stated that most of them consisted of clay and sandstones. Then based on laboratory tests, it was found that at a depth of 3 - 3.5 meters it consisted of 86.47% clay with a plastic limit of 37.07% and the water content was 39.41%, while at a depth of 9 -9.5 meters it consisted of sandstones which the characteristic is non- plastic with a water content of up to 72.04%. It is concluded that the surface soil is conductive, it is necessary to hold special treatment for this type of soil in order to avoid erosion when it is saturated with water and it is hoped that the stability of the soil will be better. One of two ways is by mixing high density soil and making a "chicken claw" foundation to strengthen the foundation with a depth of more than 5.0 meters. Keywords: Geoelectric, Standard Penetration Test, Resistivity, Chargebility, Foundation.

Thematic Maps for the Variation of Bearing Capacity of Soil Using SPTs and MATLAB

The current study involves placing 135 boreholes drilled to a depth of 10 m below the existing ground level. Three standard penetration tests (SPT) are performed at depths of 1.5, 6, and 9.5 m for each borehole. To produce thematic maps with coordinates and depths for the bearing capacity variation of the soil, a numerical analysis was conducted using MATLAB software. Despite several-order interpolation polynomials being used to estimate the bearing capacity of soil, the first-order polynomial was the best among the other trials due to its simplicity and fast calculations. Additionally, the root mean squared error (RMSE) was almost the same for the all of the tried models. The results of the study can be summarized by the production of thematic maps showing the variation of the bearing capacity of the soil over the whole area of Al-Basrah city correlated with several depths. The bearing capacity of soil obtained from the suggested first-order polynomial matches well with those calculated from the results of SPTs with a deviation of ±30% at a 95% confidence interval.

Comparison among Different Methods to Estimate Ultimate Capacity of Bored Pile

This study investigates the ultimate load capacity of concrete 1.5 m diameter bored pile based on three methods: field-loading test, field Standard Penetration Test results, and numerical modeling. A comparison of the ultimate load capacities from these methods was made (the measured large-scale field-loading test, the correlated SPT N values applying Novo SPT software and numerical modeling where Plaxis3D software with Mohr-Coulomb model was utilized). The result of the pile field-loading test was more accurate than the other methods and used as a reference for comparison among their results. In general, the value of ultimate load capacity calculated from Novo SPT software and that obtained from numerical analysis were compatible in comparison with field load results.

Standard penetration testing in a virtual calibration chamber

The virtual calibration chamber technique, based on the discrete element method, is here applied to study the standard penetration test (SPT). A macro-element approach is used to represent a rod driven with an impact like those applied to perform SPT. The rod is driven into a chamber filled with a scaled discrete analogue of a quartz sand. The contact properties of the discrete analogue are calibrated simulating two low-pressure triaxial tests. The rod is driven changing input energy and controlling initial density and confinement stress. Energy-based blowcount normalization is shown to be effective. Results obtained are in good quantitative agreement with well-accepted experimentally-based relations between blowcount, density and overburden. It is also shown that the tip resistance measured under impact dynamic penetration conditions is close to that under constant velocity conditions, hence supporting recent proposals to relate CPT and SPT results.

Optimizing site-specific geostatistics to improve geotechnical spatial information in Seoul, South Korea

Subsurface soil and rock profiles are commonly interpreted from borehole log datasets. These datasets include three-dimensional spatial coordinate information, layer information, and standard penetration test results. More reliable spatial distribution of target physical properties can be obtained from additional testing at locations characterized by outlier observations and geotechnical uncertainties. At a given site, irregular measurements typically differ significantly from bulk measurements or proximal observations. In this study, a process for optimizing site-specific geostatistics, which uses geotechnical spatial information and applies optimum outlier thresholds with a multi-clustering method, is proposed to incorporate site-specific geo-layer uncertainties and identify their geotechnical value. Optimized geostatistical characteristic information for geological strata boundaries was derived and verified based on a sequential procedure applied to representative test areas in Seoul, South Korea.

Elasticity modulus of clayey deposits estimation using group method of data handling type neural network

Elasticity modulus (Es) is used to predict the elastic settlement of foundations. Plate load test (PLT) is one of the most commonly applied methods to determine this parameter. Given that the method is relatively costly and time-consuming, especially in depths, various empirical equations have been proposed to relate the Es to the results of standard penetration test (SPT) which is one of the most frequently used tests during the geotechnical investigation. Considering that the existing relationships are not able to estimate Es properly, in the present research, Group Method of Data Handling (GMDH) type neural network (NN) is used to estimate the Es of clayey deposits based on a database including 131 plate load test (PLT) and standard penetration test (SPT) from geotechnical investigation sites in Qazvin, Iran. The comparison between proposed models and existing empirical equations indicate that the GMDH models exhibit higher performance (32–42% improvement) with respect to the other correlations. The sensitivity analysis of the developed models has been conducted to determine the contributions of the parameters affecting Es and shows that N60 is the most influential parameter on the GMDH-based models to predict Es. Also, it has been demonstrated that the Es predicted by the best model is significantly affected by error in the measurement of the LL value. Therefore, measuring this parameter in the laboratory requires high accuracy.

An Attempt of Screw Driving Sounding Test in Malaysia

Conventional soil investigation methods such as Mackintosh Probe Test (MPT) have limitations, e.g., require manual work for the equipment and data accuracy is low due to human error. While Standard Penetration test (SPT) needs high skilled workers and the cost per testing is expensive. Hence, Screw Driving Sounding test (SDS) was developed in Japan as a solution to the aforementioned disadvantages. An attempt was done to implement this test in Malaysia at different types of soils. This paper presents the results obtained from Batu Pahat and Cheras sites. Data from SDS tests were compared with the existing data of SPT and MPT available from Batu Pahat and Cheras sites, respectively. Results of the coefficient of determination, R2 = 0.721 for Batu Pahat Site and 0.851 for Cheras Site illustrate that the SPT and MPT results are highly correlated with SDS test results. From this preliminary findings, it shows that SDS test has the potential for soil characterizations in soil investigation work in Malaysia.

Determination of engineering properties of soil on railway track routes (An example of Turkey between the cities of Sivas and Erzincan)

Subsurface structure and engineering properties of the Sivas and Erzincan railway route were investigated by using velocities of seismic wave, electrical resistivity, standard penetration test (SPT) data and laboratory results, which were collected from survey sites referred to in this study. For this reason, 62 seismic refraction and vertical electrical resistivity (VES) measurements at 59 points were done along the survey route. Moreover, 11 mechanical boreholes with SPT were drilled. Laboratory tests were applied on soil samples taken from boreholes for geotechnical features. Longitudinal, shear wave velocities and elastic parameters were determined by seismic refraction method, and underground resistivity distribution was calculated by VES and geotechnical data and SPT results were evulated for the subsurface integrity. Engineering properties of a 6.8 km stretch of planned railway alignment in southeastern Sivas were calculated in this study. According to these results, unsuitable segments of the high-speed alignment which have low groundwater level and low bearing capasities which depend on dynamic properties were examined.