Plate Load Tests Research Articles

Bearing capacity and geotechnical properties of sandy soil substrate contaminated with oil derivatives (diesel fuel and kerosene)

This research investigated the bearing capacity and geotechnical properties of a sandy soil substrate contaminated with the oil derivatives diesel fuel and kerosene. For this purpose, a site with a clayey sandy soil substrate was considered to evaluate the effects of contamination on the geotechnical properties and bearing capacity of the substrate in both clean and contaminated states. Then, the substrate of the site was artificially contaminated with diesel fuel and kerosene and underwent field and laboratory tests. The experiments, including the Atterberg limits, standard Proctor compaction, uniaxial compressive strength, strength and freeze–thaw durability tests, were performed on prepared samples. Also, to determine the bearing capacity of the contaminated and intact substrates, a plate load test was conducted at the site. The results indicate that contamination by oil derivatives reduces the strength and increases the settlement and displacement of the contaminated substrate, where the effects of diesel fuel are more significant than those of kerosene. The results of this research are compared with those of previous studies. The literature shows that most research in this area was carried out in the laboratory, and there is a lack of in situ studies. This study showed that the presence of oil contaminations caused a 3.5% reduction in the soil Atterberg limits. The contaminations also reduced the dry density and uniaxial compressive strength of the soil by 2.5% and 20%, respectively. The results presented were consistent with those of other researchers. However, some studies have suggested an increase in the Atterberg limits owing to oil contaminants in the soil.

A Parametric Study on Pavement with Geocell Reinforced Rock Quarry Waste Base on Dredged Soil Subgrade

Dredging produces a vast amount of waste from water bodies worldwide, whose valorization is an environmental problem. Weak dredged soil requires some treatment to provide them with adequate strength for construction applications. In the present study, static plate load tests are conducted to understand the effect of high-density polyethylene geocell reinforcement on limestone aggregates and quarry waste on subgrade (dredged soil). Finite element analysis was carried out to compare the results with the experimental analysis. The dolomitic limestone and crushed quarry waste are waste materials readily available in the near vicinity. Static plate load tests were observed for three different geocell heights (100, 125 and 150 mm) in terms of increase in bearing capacity and vertical stress distribution for three different thicknesses of bases (120, 150 and 170 mm). This study aims to present the results in terms of load versus deformation and vertical stress distribution. The results showed that the reinforced layer had undergone a maximum reduction in deformation in comparison to the unreinforced bases. Due to the inclusion of geocell, the average bearing capacity improvement factor enhances, and the vertical stress distribution increases significantly. The average bearing increases by 50% in the case geocell reinforced test section. The results from this study suggest that rock quarry waste can be used as an alternative base material for pavement construction if proper geocell confinement is provided. The present study results will be used as a reference to support that valorization of waste can be beneficial for both nature and the economy.

Mechanical and structural performance evaluation of pervious interlocking paver blocks

Pervious concrete is one among the evolving sustainable pavement materials due to its unique storm water storage and ground water recharge applications. The present study aims to develop a Pervious Interlocking Paver Block (PIPB) and to study its mechanical, functional and structural performance. In the current explorative research work, the influence of aggregate gradation, and the percentage of fines on mechanical, functional and structural performance of PIPB were evaluated. The mechanical and functional properties such as compressive strength, split tensile strength, flexural strength, and skid resistance are assessed. The structural behaviour of the PIPB pavement section is found using plate load test and large-scale direct shear test. FEM based software, PLAXIS, is used to validate the test results. Infiltration test is conducted on the plate load test section to understand the infiltration rate. Finally, 2D image processing was performed using MATLAB to conclude the test findings. The test results proved that the grade III mix possesses desirable mechanical properties, lower deflection, higher shear strength, and required permeability. The present study affirms that the PIPB can be an effective pavement material for the low volume roads, urban heat island and pavements with drainage problems.

WITHDRAWN: Reinforced sand bed bearing capacity prediction in presence of cyclic & monotonic loading

Technique of reinforcing soil beds it was very common & old method for enhancing load keeping capability of soil & decreasing settlement. Whatever, method has been not adopted totally, as in past there has been rare researches available including this technique of design & analysis. So soil reinforcement communication should analyse properly. Possibility of technique for assuming bearing capacity enhance underground of reinforced sandy has examined through user utilizing test executed in different test situations. In the present investigation, total four different types of reinforcing materials have been used. Four model circular footings of various internal diameters are been used for investigating affect of annular ratio on bearing capability of the sand bed along different reinforcing conditions. Model plate load test have been performed under monotonic & cyclic loading in three series which are mentioned for Monotonic plate load tests on a ring footing resting on sand beds reinforced along Geogrid-Netlon-CE121 as reinforcing material- Fifteen numbers, Cyclic plate-load tests along Geogrid-Netlon-CE121 as reinforcing material - Fifteen numbers, Monotonic plate-load tests along Geo-jute as reinforcing material - Nine numbers, Cyclic plate-load tests along Geo-jute as reinforcing material - Nine numbers.

Large scale plate loading tests of refuse soil

Refuse is a type of soil composed of domestic waste and filling soils. The ch emical components of the refuse is extremely complex, and the mechanical parameters of the refuse is dependent on the local economic development, customs, climatic cond itions and geological condition. In this condition, the field tests is required to obtain th e mechanical parameters of the refuse. In this study the large sale plate loading tests w ere carried out on the refuse soils at the garbage landfill of China International Garden Flower Expo at Wuhan. Based on the tests results the influence sphere of refuse soil un der 1200T is obtained. The tests results can provide reference and guidance for the sim ilar projects.

Development and preliminary application of a plate loading model test system considering stress state

To explore the effect of stress state on the bearing characteristics of foundation soil, this study proposed a self-developed plate loading test system. The system can be used to simulate the actual stress state of foundation soil within a given stratum, achieve uniform loading or gradient loading of lateral stress in simulating the k0 consolidation state, and simulate overburden stress around the foundation under the two loading modes. This study conducted plate loading tests on siliceous sand foundation under different loading modes using this system. It was found that (Ι) the bearing capacity and deformation modulus of foundation soil measured by the system under flexible loading were greater than those measured under rigid loading. Also, foundation settlement was smaller under flexible loading. (ΙΙ) Vertical stress in foundation soil was relatively uniform under both loading modes and was more uniform under flexible loading.

Subgrade assessment using automated dynamic cone penetrometer to manage geo-infrastructures

For the efficient management of geo-infrastructures in the field, engineering properties of the subgrade should be reliably and rapidly investigated. The objective of this study is to estimate and compare the strength and stiffness parameters of subgrades using portable in-situ devices. An automated dynamic cone penetrometer (ACP), dynamic cone penetrometer (DCP), and light falling weight deflectometer (LFWD) are adopted and applied at nine points of soft ground in South Korea. The Nvalue from the ACP (NACP), which efficiently assesses the relatively deep subgrade, is correlated with the dynamic cone penetration index (DCPI) and dynamic deflection modulus (Evd). Test results show that the DCPI and Evd can be estimated in terms of NACP. In particular, the relationship between Evd and NACP is improved when the strain influence factor of the target ground is considered. For the assessment of strength and stiffness parameters, the California bearing ratio (CBR), relative density (Dr), internal friction angle (φ), and elastic moduli determined by the plate loading test (PLT), soil stiffness gauge (SSG), falling weight deflectometer (FWD) are estimated using NACP. The ACP test with the relationships between engineering parameters and NACP may be an effectively method to assess the overall characteristics of the subgrade.

Experimental research on geotechnical engineering characteristics of coral reef in Xisha Islands

Coral reefs are widely distributed in Xisha Islands, which have special engineering properties. Coral reef geology from top to bottom is coral sand, coral gravel, coral reefs calcareous rock. Coral sand and coral gravel have the characteristics of mixed size particles, alternating accumulation of sand and gravel, great change of density and gradually coarsening from top to bottom. Coral reefs calcareous rocks are composed of loose bioclasts cemented, some of them are dense, and some of them are semi-cemented and weakly cemented. The geological age of the Xisha Islands within 50m was determined by carbon-14 radioisotope isotopic test. The bearing capacity and deformation characteristics of coral sand and coral gravel were analyzed by plate loading test, heavy dynamic penetration test, extra-heavy dynamic penetration test and standard penetration test. The physical and mechanical characteristics of coral reefs calcareous rock were studied by longitudinal wave velocity test, density test, porosity test and uniaxial compressive strength test.

Evaluation of Soil Coefficients for Two-Parameter Subgrade Soil Model Based on Rigid Plate Loading Tests

Abstract Two-parameter elastic foundation models have great potential for approximate soil-foundation-structure interaction analysis. A hurdle to the wide application of this model has been the difficulty of calibrating the two soil coefficients: the compression coefficient k and shear coefficient G. This paper presents a novel parameter calibration method for k and G based on a number of rigid plate loading tests. Empirical k and G values are also recommended. Experiments showed the validity of the proposed method. Two case studies verified the significance of the two-parameter model in the prediction of footing settlement when interactions among neighboring footings exist.

Correlations between Laboratory Dynamic CBR and Compaction Parameters of Unbound Coarse Aggregate for Base Courses

Abstract It is well known that the determination of fundamental engineering properties of materials is the key to their inclusion within quality control assessments and pavement design. Although using of maximum dry density and optimum moisture content has been widely accepted in quality control assessments, it may not provide the mechanistic properties of the compacted material, namely, strength or stiffness. On the other hand, the static plate loading test used for quality control of roads is relatively expensive as compared with lighter equipment used nowadays to control the bearing capacity of compacted unbound materials. In this context, it has become necessary to find a simple and quick test that can be used in assessing the bearing capacity of Swedish base course material. For this purpose, several unbound granular California bearing ratio (CBR) samples were prepared and compacted using modified Proctor compaction for a wide range of molding water contents. Then, the CBR samples have been tested by a dynamic California bearing ratio device. This research provides a data base for future adopting of the dynamic CBR test as a light equipment used for quality assurance during roads construction. Regression equations have been developed to predict the laboratory dynamic CBR (CBRLD) from the molding water contents and the dry densities with relatively high correlation coefficients. These equations can be used in predicting the CBRLD values for unbound granular materials compacted and tested at similar conditions as in that developed for.

Regression analysis between rock moduli: case studies from the Deriner/Artvin and Ermenek/Karaman dams

Rock mass elasticity modulus, rock mass deformation modulus, static elasticity modulus, and dynamic elasticity modulus are the geotechnical properties of a rock mass and intact rock. However, these moduli are confused with each other in the literature. These moduli are determined using different test techniques. These values are different values and should not be used interchangeably. The main purpose of this paper is to illustrate the differences and build a statistical relationship between these rock moduli. The moduli determined in Deriner/Artvin and Ermenek/Karaman dam investigation studies were used and compared in this study. The rock mass elasticity modulus (ED) from the dilatometer test, rock mass deformation modulus (DD) from the dilatometer test, rock mass elasticity modulus (EH) from the plate-loading test, rock mass deformation modulus (DH) from the plate-loading test, intact rock static elasticity modulus (ELS) from laboratory tests, and intact rock dynamic elasticity modulus (ELD) from laboratory tests were correlated with regression analysis. Empirical equations obtained by the regression analysis performed between rock moduli revealed high correlation coefficients. The ratio of the modulus of deformation and modulus of elasticity determined from in situ test at the Deriner dam site was close to 1 at smaller modulus values but the ratio value was scattered at higher modulus values. The ratio of the laboratory determined dynamic elasticity modulus and static elasticity modulus approached 1 by decreasing weathering. Differences between moduli are demonstrated in this paper. The empirical equations proposed in this study were developed with a limited amount of data and every rock mass and intact rock sample have specific modulus values. The equations determined in this study should not be used for other projects or a cross check should be performed.

Layer Composition of Continuously Reinforced Concrete Pavement Optimized Using a Regression Analysis Method

A procedure for determining the optimized composition of layer properties for a continuously reinforced concrete pavement (CRCP) system was constructed using field tests, finite element (FE) analysis, and regression analysis methods. The field support characteristics of a rigid pavement system were investigated using a falling weight deflectometer (FWD), dynamic cone penetrometer (DCP), and a static plate load test. The subgrade layer exhibited a more uniform condition than the aggregate base, and the modulus of the subgrade reaction of the aggregate base and subgrade combination (effective k-value) was improved by about 1.5 times by introducing a 2 inch (50.8 mm) asphalt stabilized base (ASB) layer. Thereafter, FE support models describing the actual field conditions were studied. The effects of the thickness of the stabilized base layer, the elastic modulus of the stabilized base material, and the effective k-value on the composite k-value of the support system were identified using a regression analysis method, and the results showed that the variables had a similar effect when determining the composite k-value. Afterward, a procedure for selecting the layer properties for producing a suitable composite k-value was constructed, and we identified that the maximum stress in the concrete slab was induced at different levels, even with identical composite k-values. Lastly, regression relationships were derived to estimate the maximum stress in the concrete slab by considering both the support layer properties and the concrete slab. Subsequently, an algorithm for selecting an optimized layer composition of the CRCP structure was construction considering the economical aspect.

Static and dynamic plate loading tests of stabilized soil samples used for riverbank consolidation

Building of an experimental slope protection system on Căpuş river, near Cluj presented the opportunity of in situ testing of stabilized soils. Different hydraulic binder was used on each side of the river, so this testing series provided valuable data about deformability properties of the encountered soil types. There are some deformability parameters used in Romania which were “imported” at the specific request of foreign investors. The strain modulus, Ev, is a parameter expressing the deformation characteristics of a soil and is calculated taking values from the load-settlement curve obtained from the first and second loading cycle, on a static plate load test. In earthworks, the dynamic plate load test using the Light Falling Weight Deflectometer may be used for testing load-bearing capacity as an alternative to the static plate load test which provides the strain modulus, Ev parameter. Dynamic modulus of deformation Evd is a parameter for the deformability of soil under a defined, vertical impact load with the impact duration. Its value is being calculated with the maximum settlement of the load plate. None of these methods made way into official Romanian standardisation, the Evd is subject of a technical agreement, which also contains the correlation of it with Ev. Conducting both static and dynamic loading tests enabled the verification of validity of relation between strain modulus and dynamic modulus.

Dynamic compaction of the Baltic basin silty Sand - quality assurance with CPT, DPM, DMT and PLT

Post-glacial evolution of the Baltic basin sedimented Quaternary soils at the great thickness (up to 30 m) in Riga, Latvia. There are present zones of different combinations of postglacial, alluvial, limnological and dune formations within the metropolitan area of Riga. The geomorphological evolution of this territory is dominated by the Baltic sea former stages, distinguishing these areas as rather complicated. The dynamic compaction was proposed below the warehouse floor of area about 40K m2 in Baltic basin silty Sand. The effect of compaction was evaluated to the depth of 10 m and extensive quality assurance using cone penetration and piezocone tests (CPT(U)), dynamic probing (DP) tests, flat dilatometer tests (DMT) and plate loading tests (PLT), was introduced. CPT(U) and DMT results were compared in terms of soil stiffness parameter evaluation prior and after dynamic compaction. The limitation of DP tests were investigated and finally also warehouse test embankment verified by PLT evaluating shallow compaction rates.

TBM-spoil characterization and utilization at the Follo Line project

The potential use of surplus materials commonly considered as waste has been investigated by the project “Geomaterials in the Circular Economy” (GEOreCIRC). TBM spoil is one of the materials which were assessed, based on data from the Follo Line tunnel project in Oslo, Norway. For this tunnel, four TBMs were used simultaneously and the tunnel generated almost 9 million metric tonnes of spoil. The excavated TBM spoil was used to establish a building platform for a new district in the Oslo municipality, by filling a 30 m deep valley. An extensive campaign of laboratory testing, field measurements and monitoring was conducted for the deposit. The geotechnical properties, such as grain size distribution, grain shape, brittleness, density, permeability and friction angle were determined. The optimal water content for compaction and maximum dry density were determined using the Standard Proctor test. Field measurements included plate load tests and nuclear density gauge (Troxler), with several measurements for each layer of the deposit. In addition, the spoil was analysed for a wide range of possible contaminants associated with natural rock minerals and machinery used in the tunnelling process. The results show that the level of contamination is low, and related to background levels from the bedrock itself, with levels below specified threshold values for contaminated soil according to Norwegian regulations.

Strength and stiffness properties of stonewool used as cloudburst reservoir under roads

With the climate change, Copenhagen has seen an increase in cloudbursts. During the cloudbursts, sewer systems overflow and result in flooded basements and overspill of untreated water into the harbour. A solution to the limited capacity is to make cloudbursts reservoirs to delay the rain water filling the sewer system. At Langelands Plads in Copenhagen, a reservoir has been established using the stonewool product Rockflow. The Rockflow is installed under two roads and a space used for recreational purposes. Based on monotonic and cyclic laboratory tests, material parameters and appropriate numerical model for the anisotropic material were established. In-situ measurements of the stiffness during and after installation at Langelands Plads consisted of plate load tests and falling weight deflectometer tests together with rutting measurements. The in-situ measurements were statistically processed and back-analysed to confirm the initial material parameters and model. Further, the in-situ measurements are ongoing at appropriate intervals to monitor the performance of the road.

Evaluation of Dissipated Energy in Rock Mass under In-Situ Plate Load Test

Evaluation of Dissipated Energy in Rock Mass under In-Situ Plate Load Test

An Investigation of the Mechanisms Involved in Plate Load Testing in Rock

Accurate determination of rock mass deformation modulus is very important in rock engineering projects. The plate loading test (PLT) is a method that is generally used in dam construction projects to determine rock mass modulus. Numerical simulation was used to investigate the mechanisms involved in this test. The first objective of the paper was to employ 3D modeling in the interpretation of plate load tests conducted at the Bazoft dam site in Iran. Additionally, a parametric study of the effects of key parameters such as displacement measuring depth and loading plate diameter on the test results was another objective of the study. The moduli values determined numerically were compared against actual filed testing data determined from in-situ test data conducted at the Bazoft dam site, and the values determined from the ISRM suggested formula. The analysis showed that the optimum measurement depth for rock mass modulus calculation is approximately equal to the loading plate diameter and the data determined from measurement depths beyond one plate diameter can be unrealistic. Moreover, the plate diameter can have a significant effect on test results. As the measurement depth increases, the determined modulus values increase at a much more rapid pace when employing smaller size loading plates.

Prediction Models Based on Regression and Artificial Neural Network for Moduli of Layers Constituted by Open-Graded Aggregates.

The impermeable cover in urban area has been growing due to rapid urbanization, which prevents stormwater from being naturally infiltrated into the ground. There is a higher chance of flooding in urban area covered with conventional concretes and asphalts. The permeable pavement is one of Low-Impact Development (LID) technologies that can reduce surface runoff and water pollution by allowing stormwater into pavement systems. Unlike traditional pavements, permeable pavement bases employ open-graded aggregates (OGAs) with highly uniform particle sizes. There is very little information on the engineering properties of compacted OGAs. In this study, the moduli of open-graded aggregates under various compaction energies are investigated based on the Plate Load Test (PLT) and Light-Weight Deflectometer (LWD). Artificial Neural Network (ANN) and Linear Regression (LR) models are employed for estimation of the moduli of the aggregates based on the material type and level of compaction. Overall, the moduli from PLT and LWD steeply increase until the number of roller passes reaches 4, and they gradually increase until the number of roller passes becomes 8. A set of simple linear equations are proposed to evaluate the moduli of open-graded aggregates from PLT and LWD based on the material type and the number of roller passes.

Full-scale laboratory tests of geosynthetic reinforced unpaved roads on a soft subgrade

In this study, a large-scale laboratory test was developed to analyze the contribution of geogrid reinforcement to the improvement of unpaved roads. A detailed experimental protocol was established regarding the road base soil preparation, installation, and soil compaction procedure. Eight tests were performed under a circular plate load test in a box 1800 mm in width, 1900 mm in length, and 1100 mm in height. Under this configuration, three repeat tests were performed to verify the developed protocol. Furthermore, the plate load tests were used to compare different road base thicknesses and geogrid types. Once the developed protocol was confirmed, three tests, using the developed simulator accelerator of traffic (SAT), were performed. Indeed, the same road base configuration was tested, but this time it was placed in a box 5000 mm in length. The prepared road base was subjected to two different loadings: a specific plate load and a traffic load. The results showed the efficiency of the geogrids, the influence of the road base thickness, and the role of the loading type. Moreover, it demonstrated different mobilized mechanisms of the geogrid, depending on the type of product.