Soil Testing, Soil Stability and Ground Improvement

The objective of our work is the study of the influence of the dynamic load due to the use of the explosive in the stability of the slope of an open pit mine, for this purpose we used the method of limit equilibrium to calculate the value of the safety factor through the geotechnical software SLIDE. On the one hand the calculation was carried out under static loading and on the other hand the dynamic loading is taken into account, which allowed us to conclude that the dynamic load influences the safety coefficient. Finally, a proposal to stabilize the slope at through a reprofiling of the bench is presented.

This paper presents a validation of simplified design approach against a field study and a laboratory test. The design approach has been developed to predict drained settlement and the ultimate bearing capacity of stone columns supported foundation adopting a hyperbolic relationship to simulate the strain hardening behavior. The result of a plain footing load test is required to give two curve fitting parameters and then adapted them by introducing a reduction factor which take into account the length ratio and the area replacement ratio to predict the stress-strain characteristic of a stone column supported foundation. Good agreements are found when the predictions using the simplified approach are compared with the laboratory testing and field case study.

The present paper comments on the evaluation of the initial stiffness of sensitive soft soils as an outcome of several testing methods: Resonant Column (RC), Bender Element (BE) tests, Seismic cone tests and Empirical relationships (correlations). The RC, BE and common geotechnical laboratory tests were carried out on soft clays adjacent to the Tunis Lake in Tunisia. The database was completed making use of existing studies carried out on other types of Swedish soft clays from the literature related to seismic cone tests. A number of empirical correlations for determining the initial value of the shear modulus of soils in the literature was adopted in order to re-analyze the available data set. The authors suggested an adapted empirical lower bound correlation aiming at evaluating the analyzed soft soils’ small strain shear modulus (G_max), probably even useful for less undisturbed sampling. The proposed equation aims at giving an indication of the effect of, for example, the mean effective stress (p′) and the corresponding void ratio (e) on the initial soil stiffness more clearly.

Soil collapsibility or soil swelling is typically measured in the laboratory by using a single or double consolidation test. Such a test requires time and is costly: its stages include preparing the samples, transferring them to the laboratory, and conducting related tests. In most cases, geotechnical engineers have to carry out experiments during the stage of site investigation to evaluate the soil in terms of collapsibility. However, soil collapsibility might be easily estimated by a simple desert test. The device designed, developed, and used by the authors of the present study has the ability to determine the soil’s collapsibility and offers its primary percentage. The experiments that were conducted on the downstream alluvium of Seevand Dam, with high collapsibility, to assess the performance of the device indicated that the device is able to appropriately evaluate the collapsibility of soil. Furthermore, comparing the results of these experiments with those of experiments using the consolidation method confirm the accuracy of the findings present study, with a high percentage. Given the probability of disturbing soils in laboratories, it might be contended that this device obtains results that are more valid than laboratory results.

Seasonal climatic variations in subgrade soil affect pavement responses and can reduce pavement serviceability. In addition to causing shrinkage and swelling in expansive subgrade, variations in moisture suction may alter the material properties of soil, which ultimately affect pavement performance. The current study monitored the seasonal variation of subgrade moisture content, rainfall, and pavement deformation of a section over State Highway 342, in Dallas, Texas. Moisture sensors were installed at different depths up to 4.5 m. The soil was found to be highly plastic clay (CH) in the selected site. In addition to acquiring real-time moisture data from sensors, geophysical testing was also conducted on the slope of the pavement. Electrical Resistivity Imaging (ERI) was carried out at the slope of the instrumented pavement section to observe the moisture flow at the edge of the pavement. Based on the field monitoring data, moisture variation ranged from 5% to 14%, with higher moisture contents correlating with rainfall events. While moisture sensors provided point information, resistivity imaging yielded a continuous portrayal of subsurface moisture flow. Furthermore, rainfall-associated deformation of the pavement was monitored. Based on the monitored data, it was observed that pavement deformation varied with rainfall. A total deformation of 38 mm was recorded over the monitoring period.

River sediments are mainly composed by intermediate materials, between sand and clay, for which partial drainage conditions apply. In these cases, the interpretation of CPTU tests may be wrong since existing correlations are based on fully drained or fully undrained conditions. This paper presents results from CPTU tests performed in a river area to evaluate whether partial drainage conditions were observed. The results, presented in terms of the normalized velocity, show that great part of the analyzed profiles are in this condition. For this reason, the angle of shearing resistance was presented as a conservative estimate of the soil strength in these areas.

In times of increasing concern for the environment, the CO₂-footprint method is widely accepted to evaluate the use of greenhouse emitting production processes for a given product. This allows for comparisons between products and makes environmentally friendly choices of a product more transparent to decision makers.In the field of slope stabilization, the high tensile steel wire mesh TECCO® in combination with soil or rock nailing is the state of the art in many countries. Compared to shotcrete, load transfer capacity is equal or higher. The open mesh leaves enough space for plants to grow through the system.Recent CO₂-footprint evaluation taking into account production and transport of the material of an equivalent slope stabilization measure shows that the TECCO® system has a very low CO₂-footprint. The methods used for assessing the impact were, the level of carbon dioxide emissions from burning of fossil fuels as well as all other emissions which contribute to climate change. These other emissions have been recorded and weighted according to their specific contribution to give an overall index, “Global Warming Potential” (GWP). Compared to shotcrete, the CO₂-footprint of the mesh solution is 4–5 times lower! One reason for the good result is the high CO₂-emitting level of concrete in general. Furthermore, less material weight and also transport costs for the same stabilizing effect of the product on the slope also account for a better CO₂ balance of the mesh solution.

Stone columns are recognized as an environmently-friendly and cost-effective ground improvement technique. Stone columns are used in soft soil to increase the bearing capacity, reduce the settlement, increase the rate of settlement and reduce the liquefaction potential of the ground.This paper presents an analytical model utilizing the method of slices to predict the ultimate bearing capacity of the soil reinforced with a group of stone columns. The soil within the failure zone was divided into slices and the limit equilibrium technique was adopted to perform the analysis. Shear forces and passive earth pressure on the boundaries of each slice were determined. By utilizing a circular failure plane, the minimum inter-slice force coefficients were determined.The analysis was carried out using the Morgenstern-Price method to estimate the failure surface together with the bearing capacity of the reinforced ground. The failure surface was determined by trial and error to estimate the minimum factor of safety. The ultimate bearing capacity was defined by increasing the foundation load until the factor of safety of one was obtained. Results of the present theory were compared with those available in the literature, where a good agreement between the two was noted.

In geotechnical engineering, the problem of laterally top-loaded piles occurs frequently. This type of foundation is often used in highly porous, collapsible soils, which are common in several regions of Brazil. Because of the limited information available in the literature, several load tests have been performed on piles subjected to this load. To analyze the behavior of piles in these collapsible soils, load tests were performed in steel piles (I), W 250 × 32.7 section (mm × kg/m), length 12 m, conventional bored piles (ϕ = 0.40 m; L = 12 m) and continuous helical auger piles (ϕ = 0.40 m; L = 12 m). All of them were tested at the same site. For each type of pile, a first load test was carried out with the soil in its natural condition of moisture content, followed by a second load test after the surface soil was flooded for 48 h. The results indicated a significant negative effect of flooding on the topsoil which consisted of sandy-silty clay with collapsible features down to the depth of 6 m. Load vs. horizontal displacement curves and soil coefficients of horizontal reaction were obtained. The results allowed the proposal of parameters for use in the soil under study. Before executing the load tests, laboratory and in-situ tests were performed to investigate the local subsoil.

DMT was used for three main applications in famous projects in Dubai, UAE and in Duqm Port in Sultanate of Oman in the Arabian Gulf. The 1st two applications were conducted in man-made sandy earthfill embankments formed by dredging from the sea bed and stabilized by deep ground improvement. The recent correlations of S. Marchetti to incorporate the DMT stress history parameter K_D for CPT-based CRR was used to confirm post-compaction CPT-based liquefaction analysis in the Duqm Site, whereas DMT was used in Dubai site to confirm the over consolidated nature of upper sandy fill soil that was previously Vibro-Compacted (8–10 years). On the other hand, the design of large diameter flexible steel oil storage tanks is based on controlled & strict, edge settlement requirements. Without DMT, the estimates of soil modulus are made based on SPT or CPT tests resulting in conservative estimates, and suggesting the need for deep ground densification/improvement. Site specific correlation was developed for a large site between DMT based M and CPT tip resistance (qc) indicating at least 50% increase over the CPT based M.

Mumbai marine clay is problematic in nature for substructures and it needs to be strengthening before making it available for any construction activity. Out of many available geotechnical solutions, stone columns are quite handy in significantly improving the bearing capacity of marine clay, which also supplements by dissipating excess pore water pressure and reducing the settlements of clay beds under external loads. For the investigation on behavior of stone columns, marine clay was collected from the Uran site near Mumbai, India. Slurry consolidated clay beds were prepared and gravity loading mechanism was adopted to consolidate the clay beds in the laboratory. Laboratory tests were performed to ascertain the uniformity and repeatability of the clay beds by slurry consolidation. Augers of 50, 75 and 100 mm diameter were used to bore the holes in the clay bed and aggregates were used for stone column preparation by replacement method. The static displacement controlled tests were performed on the stone column reinforced clay bed. In the present study, the loading is applied on stone column alone, as it leads to the ultimate axial capacity of stone column improved ground. Clay bed reinforced with stone column exhibits improved load-settlement response, compared to unreinforced clay beds. The improvement was very significant at higher settlements. The failure load of reinforced clay bed is around 6 times more than the unreinforced clay bed. In order to further understand the behaviour of stone column reinforced ground, numerical modeling of stone column reinforced clay bed is conducted using FLAC3D. Using the validated numerical model of the stone column, the effect of variation of the diameter of stone column on its performance was studied. From the numerical analysis and physical tests conducted in laboratory, it is observed that the stone columns with smaller diameter when subjected to vertical loading carried higher bearing pressures when compared to that of the larger diameter stone columns, which may be due to the greater confining and larger bulge formed at a depth of 2–3 times the diameter of stone columns.

Surficial failures of highway slopes in clayey soils are quite common throughout the United States. These failures commonly occur for the slope constructed with expansive clay, especially after prolonged rainfall. These failures are also predominant in North Texas area and cause significant maintenance problems for the Texas Department of Transportation (TxDOT). As an alternative to the conventional slope stabilization technique, a green and cost effective slope stabilization method using the Recycled Plastic Pin (RPP) had been utilized and tested for its performance. RPPs are driven into the slope face to provide additional resistance along the slip surface, which increases the factor of safety against shallow slope failure. Current study summarizes the long term performance of a highway slope on expansive clay reinforced with RPP. The slope is located over US 287 near the St. Paul overpass in Midlothian, Texas. Surficial movement had taken place over the slope, resulting in cracks over the shoulder and near the bridge abutment. Three 50 ft. slope sections were stabilized using RPPs in March 2011. In addition, two 50 ft. unreinforced control sections were utilized between the reinforced sections to evaluate the performance of slope sections stabilized with RPP. After installation of the RPPs, the performance of the slope was monitored by using instrumented RPPs, inclinometers and topographic survey. The performance monitoring results indicate that, maximum deformation of the reinforced slope section is less than 3.75 cm (1.5 in.). However, more than 38 cm (15 in.) of vertical settlement was observed at the control sections during the last 5 years monitoring period. Also, few slope-sections just opposite side of reinforced slope at the same highway failed during the monitoring period. Based on the last 5 years monitoring data, it was summarized that RPP can be successfully utilized for slope stabilization.

Although Nickel ores are generally characterized as plastic to very plastic silts they do liquefy under specific conditions. In fact, it was reported that New Caledonian Nickel ores (NCNo) can undergo liquefaction during their maritime transportation under wave motions. The purpose of this research is to develop a new empirical method to evaluate the liquefaction potential of these soils. First, the study consists on interpreting physical and mechanical characterization tests carried on Nickel ore samples originating from different sites of New Caledonia. This analysis permitted to conclude on the heterogeneity of NCNo and enabled the identification of three major types namely, laterites, earthy and grainy saprolites. The classification of these groups was based on the grain size distribution and the Atterberg limits tests. Afterwards, a review of the existing liquefaction potential evaluation methods is elaborated. The application of these methods to the case of NCNo has not allowed concluding on the liquefaction susceptibility of this material. Finally, a new method specific to each NCNo type was introduced based on the physical and mechanical test results.

This work is divided into two folds. The first stage was to carry out a statistical study of geotechnical soil parameters obtained for a housing project. This comprised analysis of the mean, standard deviation, coefficient of variance, histograms, cumulative densities and normal distribution laws. In addition correlation using linear regression analysis was carried out between pairs of soil parameters obtained from laboratory tests. Then autocorrelation functions were developed for pressuremeter modulus.The second stage was to develop a probabilistic approach to design shallow foundations. This assumed that strengths parameters such as cohesion and angle of shearing strength are variable. The results were compared to traditional techniques based on Terzaghi methods such as DIN and DTU and also to semi probabilistic approach such as Eurocode.

Unsaturated surface soils with porosities above 50% cover great extensions of areas in Midwest Brazil. Because of their large volumes of voids, these soils undergo great strain under loads. In addition, many of these soils are collapsible, i.e., when the soils are under load and in case of a significant increase in the moisture content or saturation of the soil, the structure collapses, thus producing unacceptable displacement values for the buildings. Because of these characteristics, problems often occur in industrial floors, pavements and other types of slabs on ground and shallow foundations. To solve this problem, compaction of the topsoil is performed before starting the construction. For this study, the soil characteristics are analyzed using both geotechnical laboratory tests and field tests in order to predict the soil behavior in terms of deformability, resistance and collapsibility.The study was conducted at the experimental site located at the State University of Campinas - Unicamp, in the municipality of Campinas, State of São Paulo, Brazil. The geotechnical properties of the subsoil were determined by collecting undisturbed samples down to 8 m in depth and deformed samples up to 9 m of depth (impenetrable). Simple recognition surveys were performed: standard penetration test (SPT) and electric static cone penetration test (CPT).The edometric tests conducted on undisturbed samples with flooding at different levels of stress revealed collapsible characteristics of the soil. With the conduction of tri-axial tests (CU), numerical values were obtained for the angle of friction and the cohesion intercepts for each depth. Paschoalin Filho (2008) verified a significant reduction in these values with soil saturation.The influence of soil deformability and of the type of load on industrial floors is analyzed. The results indicate huge influence of soil deformability in the case of distributed loads, and a minor influence in case of concentrated loads.The thickness of the compacted soil layer is very important to the definition of the modulus of subgrade reaction (k) for the studied soil.

Although tank construction is well advanced in the Middle East, not all tanks are located on suitable grounds, and many require the implementation of specific foundation measures to ensure that design specifications are satisfied. While ground improvement of tank foundations in the region has a proven track record that dates back to the 1980s, and can potentially be the most appropriate solution for many tanks, it is the authors’ experience that occasionally the projects’ settlement requirements appear to have been influenced by building specifications that have not been developed for the purpose. Consequently and unnecessarily, more expensive solutions with longer construction schedules may have to be adopted that will not bring any additional benefits to the foundation solution. This paper initially reviews settlement criteria of a number of internationally recognized standards and then presents a number of case studies of tank foundation improvement by dynamic compaction and quality control by Menard pressuremeter tests.

In this paper subgrade materials from different locations in Nigeria were characterized for use in the Mechanistic-Empirical Pavement Analysis and Design. The engineering properties of the coarse-grained Nigerian subgrade soils materials were obtained in the laboratory. Seven selected resilient modulus constitutive equation for estimating the resilient modulus of coarse-grained subgrade soils were used to estimate the default values using the repeated load triaxial test result conducted on coarse-grained Nigerian subgrade soils. These default resilient modulus parameters developed can be used to estimate the resilient modulus of the compacted subgrade soils with reasonable accuracy and utilized as level 3 resilient modulus input for Mechanistic-Empirical Pavement Analysis and Design.

Finite element analysis incorporating the shear strength reduction method was applied to study the west slope stability of an open cut mine in Australia using Mohr–Coulomb and generalized Hoek–Brown criteria. The pit of the mine had multiphase excavations and reached 180 m in depth. The study investigated three slope configurations, namely, Stage 1 inter ramp slope 43°, Stage 2 inter ramp slope 49° and optimized Stage 2 slope 54°. When implementing the generalized Hoek–Brown failure criterion, the equivalent factor of safety was 1.96, 1.87 and 1.40 under dry slope for the three configurations, respectively. However, under partly saturated conditions, the optimised slope would have a factor of safety 1.16. Furthermore, the generalised Hoek–Brown criterion generated lower factors of safety than the Mohr–Coulomb failure criterion. The difference is related to an overestimation of the shear strength parameters by the linear Mohr–Coulomb criterion under low confining stresses compared with the non-linear Hoek–Brown.

Stone columns have been increasingly acknowledged as one of the viable foundation techniques in soft ground conditions. The concept behind this option is to enhance soft soils by insertion of special elements stiffer than the original soil. The stiffness of the improved ground depends on the geometry of the stone columns in addition to the relative stiffness between the original soft soil and the installed elements. Back analysis of case histories is always a successful and reliable approach in studying the in situ behavior of different ground improvement methods. In this paper, a well instrumented case study of floating stone columns installed in the Bothkennar soft clay formation is studied using numerical modeling utilizing the finite elements method. Different soil constitutive models are investigated to define the most appropriate one in simulating the actual Bothkennar soft clay behavior. Results of the comparison between the monitored field performance and the estimated behavior from the numerical model using different constitutive models are presented and discussed, while recommendations for the most suitable stress strain model of the studied clay are concluded.

The pressuremeter test is an in situ controlled load-deformation test that is performed on the wall of a borehole using a radially expanded cylindrical probe. From the test readings (volume variation based on controlled pressure), a plane deformation stress‐strain curve can be obtained for the soil.Since the initial prototype, the pressuremeter has consistently been improved in its design, and the latest version of the pressuremeter, which is called the “auto-controlled Pressuremeter” has been developed to address the issues of repeatability and accumulation of approximations in a test. This apparatus is fully automatic and autonomous, and manages all steps of the test as instructed by the operator. The auto‐controlled Pressuremeter simplifies the work procedure for the operator, reinforces the reliability of the results, and reduces the time of set up.The present paper describes the auto‐controlled pressuremeter, and compares it with the manual pressuremeter. The first part of the paper compares the deficiencies of the manual and auto‐controlled Pressuremeter. In the second part, test results of the two types of pressuremeter that have been performed in similar conditions are presented and commented.

The Light Falling Weight Deflectometer (LFWD) load test has been developed to directly estimate the in-situ elastic modulus of near surface profiles as foundation, and subgrade layers is presented in this paper. For this purpose, field tests were conducted on selected sections from landfill project within Anbar province. In addition, forty test sections were constructed and tested at the Civil Engineering Department- University of Anbar. All sections were tested using the ZFG 3000 model - LFWD in companion with the Plate Load Test (PLT) that were used as reference measurements. Regression analyses were conducted to determine the best correlations between the elastic modulus obtained from LFWD and PLT tests., E_vd. ANN model is used to calculate dynamic deformation modulus, E_vd and comparing with the regression statistical model. The results indicate that ANN model have the capability of predicting dynamic deformation modulus, E_vd with a high degree of accuracy. Good correlations were obtained, which demonstrated that the LFWD can be reliably used to predict the modules obtained from plate load test and degree of compaction values, and hence can be used to evaluate the stiffness/strength parameters of shallow subgrade layers.

Soil is a complex material with different minerals present in variant proportions, since it is formed due to weathering of rocks. The proportion of mineral governs the behaviour of soils. The soils with Montimorillonite mineral are more expansive in nature. The structures build with or on these soils are prone to problems like cracking, foundation failures due to their Swelling and Shrinking behaviour. Stabilization of expansive soil using admixtures is effective way of improving the intended soil properties and strength in specific. This paper focuses on the performance of Fly Ash and Quarry Dust as admixtures to the selected expansive soil. Laboratory investigations for determining Atterberg Limits, Compaction Characteristics, Deformation behaviour and Unconfined Compressive Strength and mineralogical analysis are performed by Scanning Electron Microscope (SEM) technique. The general behaviour of soil alone and after admixing with different percentages of Fly Ash and Quarry Dust are analyzed from laboratory test results and cross checked from Scanning Electron Microscope studies on the selected expansive soil.

This paper presents explicit expressions for the principal effective stresses generated around a cylindrical cavity expanded in plane strain and undrained conditions in Modified Cam Clay. The assumption made in the present analysis is that Poisson’s ratio v′ remains constant throughout the shearing process. Theoretical expressions are applied to the simulation of a cylindrical cavity expansion test in K _o normally consolidated remoulded Boston Blue Clay modelled as Modified Cam Clay. The results, which are compared to those obtained by assuming that the shear modulus $$ G^{{\prime }} $$ remains constant, show that the two approaches are quite similar.

Geological medium is an open system which is influenced by outer and inner factors that can lead it to a unstable state. That non stability is as a rule occurred locally and these zones are named as dynamically active elements, which are indicators of potential catastrophic sources. These objects differ from the embedded geological medium by their structural forms, which often are of hierarchical type. The process of their activisation can be searched, using wave fields monitoring. For that purpose it is needed to develop new algorithms of modeling wave field’s propagation through the local objects with hierarchical structure. Also it is needed to develop new theory of interpretation the wave field distribution for defining the contours of these local hierarchical objects. It had been constructed algorithms for 2D modeling of sound diffraction and linear polarized transversal seismic wave on an intrusion of hierarchic structure, located in the layer number J of N-layered elastic medium. We used the method of integral and integral-differential equations for a space frequency presentation of wave field’s distribution. It is developed an algorithm for constructing the equation of theoretical inverse problem for 2-D electromagnetic field of E and H polarization and linear polarized longitudinal elastic wave by excitation of the N-layered conductive or elastic medium with hierarchic conductive or elastic inclusion located in the ν-th layer. From the theory it is obviously that for such complicated medium each wave field contains its own information about the inner structure of the hierarchical inclusion. Therefore it is needed to interpret the monitoring data for each wave field apart, and not to mix the data base. These results will be the base for constructing new systems of monitoring observations of dynamical geological systems. Especially it is needed to prevent rock shocks in deep mines by their exploitation.

A huge network of rural roads is being developed in India under the most ambitious Prime Minister’s rural connectivity programme, PMGSY (Pradhan Mantri Gramin Sadak Yojna). Under this programme, thousands of kilometers of rural roads are being constructed in the country, which require good quality pavement materials like crushed stone. The scarcity of natural aggregates has compelled to use marginal materials or locally available soils in structural layers of these pavements, which would reduced the cost of the project. Granular lateritic soils are widely available in many parts of India and presently, this is also used as sub-base material in different rural road projects, where it satisfies the code specifications. However, granular lateritic soils of some locations do not satisfy the strength and plasticity requirement of sub-base layer. But, they can probably be made suitable through stabilization. Though stabilization of soil by cement or lime is a well known process of improving the strength and stability of soil, the strength and stiffness parameters of stabilized lateritic soils in terms of modulus of rupture, resilient modulus, flexural modulus have very limited reference in literature. Therefore, in this study an attempt has been made to characterize the cement stabilized lateritic soils for use in sub-base and base layers in rural road pavements. A comprehensive laboratory testing programme has been conducted on cement stabilized granular lateritic soil samples collected from five different places of eastern India to study various strength parameters such as compressive strength, modulus of rupture and stiffness properties in terms of flexural modulus of cement stabilized granular lateritic soil. In this paper, strength and stiffness developments of cement stabilized granular lateritic soil in 7 days and 28 days have been studied and its suitability as a structural layer in rural roads has been investigated. Suitable modulus values of cement stabilized granular lateritic soils have been proposed which can be used as an input parameter for the input in mechanistic design of roads. Also relationships have been proposed to determine modulus of rupture and flexural modulus of cement stabilized granular lateritic soil from its compressive strengths.

Rapid growth of infrastructure viz., construction of highways, embankments limits the construction on varied soil conditions. The construction sites at times pass through weak/expansive soils. In order to overcome weak and problematic sub grade world over, soil stabilization becomes inevitable. In this connection, mechanical stabilization of clayey soils is explored with partial replacement by Vitrified Tiles Sludge (VTS), an industrial waste. In this experimental study, expansive soils samples are collected from Palakol town in the West Godavari District, Andhra Pradesh, India. The experiments showed significant volume changes in the soil with a change in water content, corresponding decrease in strength and significant increase in compressibility. The current experimental investigation studies the variation in the geotechnical characteristics of expansive soil modified with sludge formed by crushing vitrified tiles (VTS) in aqueous medium. Our study reveals that there is a significant decrease in compressibility characteristics of the clay with an increase in the proportion of vitrified tile sludge. The composite soil proves to be good construction material for construction of various civil engineering structures such as embankment, earthen dams, and runways wherever the decrease in swelling and plasticity are the real targets.

Part of an overall $2.4 billion dollar, multi-use, brownfield redevelopment project along a major river and highway system in the Borough of Sayreville, New Jersey, USA, was a need to conduct ground improvement activities for approximately 40 acres of the 440-acre project for a large retail structure and portions of the roadway system. During the course of subsurface explorations it was determined that a 40-acre portion of the project contained 4 to 14 ft of titanium dioxide overlying highly compressible organics. The titanium dioxide materials were the result of abandoned plant processing activities in the production of white paint pigments.The ground improvement program consisted of mixing the titanium dioxide byproduct, in-place, with Portland cement. The mixing was conducted using large excavators mixing set dimensioned cells to required depths. Over 375,000 cubic yards of materials were mixed in-place using this method. Many lessons were learned regarding design and construction considerations to overcome air quality, Portland cement delivery, mixing thoroughness, mix strength testing and quality control.Once in-place cement mixing was completed a full-scale, 28-acre surcharge program was implemented to consolidate the underlying compressible organics to support the proposed development. The surcharge program was accomplished using prefabricated wick drains (PWDs) and surcharge fills consisting of Processed Dredge Materials (PDM). PDM typically consist of river and harbor dredge spoils mixed with at least 8% cement prior to reuse as fills. The surcharge program is being remotely monitored 24/7 through the use of digital piezometers, settlement plates and in-place inclinometers via a project website.

According to the development law of high embankment settlement, the Pearl curve model is established. Combined with specific engineering example, the Pearl curve well reflects the change process of high embankment settlement, and the prediction result of the model with the measured settlement value is very accurate and reliable.

According to the development law of high embankment settlement, the Gompertz curve model is established. Combined with specific engineering example, the Gompertz curve well reflects the change process of high embankment settlement, and the prediction result of the model with the measured settlement value is very accurate and reliable.

The soft clay has the characteristics of high compressibility, high water content, low strength and poor permeability, which will lead to large settlements under long-term loads, therefore, the prediction of settlements of soft clay roadbed has been one of the important research topics in Geotechnical Engineering. In this paper, the commonly-used methods in practice to predict the settlements of soft clay roadbed have been summarized, and the advantages and disadvantages have been evaluated.

This article presents part of the results and discussions of the geotechnical studies carried out in the area and in materials collected in the BR 135 in the section between the counties of Manga and Itacarambi in the state of Minas Gerais. The study consisted in the execution of field work and laboratory work. In the field investigations were performed (auger, SPT and rotary), collecting material (soil and rock), densities “in situ” and identification/tactile-visual classification of materials. In the laboratory, with soils and rocks collected, were performed additional tests necessary to the design and implementation of the road in question, in that stretch. The studies focused along the existing highway axis and the track side, and side guidance in the predicted contours, concentrated deposits of soil, deposits concentrated of gravel, sands deposits and deposits of rocky material. With implementation of Auger investigations, it was found that the soils tactile-visual characteristics are similar to the predominance of yellow/red sandy soils. It was found that along the highway there are competent rocky material and also friable, mixed, which are not local, but come from deposits in the region and which were used in the primary coating of the road. In the carrying out field work, was done a broad recognition of the BR 135 insertion region that recognition was found that the region is covered by a wide layer of typical sandy soil (Red and Yellow Latosol). In the case of rocky material, it was found that there is a high occurrence of carbonate rocks in the region. This rock is exploited and used as building material, especially on pavements and as aggregates for concrete (Gravel 1, 2 and Gravel Gravel powder). Being a characteristic rock materials in the region, it was used for granulometric tests of sand equivalency, organic matter content, form of content, durability, abrasion “Los Angeles” and adhesiveness. The check of sands deposits, local people reported that most of the sand used in the region comes from dredging the San Francisco River in the municipality of Itacarambi. two locations sands were also collected in the municipality of Mango, also the banks of the São Francisco River.

This article presents the results of geotechnical studies and proposals to stabilize embankments referring to cuts 16, 23, 25, 30 and 31 of the BR-010 referring to Aparecida do Rio Negro a Goiatins, State of Tocantins. The study consisted in the execution of a field incursions program for verification of geotechnical conditions along the indicated stretch, running lab tests, and stability analysis of embankments in order to indicate solutions to cuts made necessary for the completion of the highway. In terms of characterization of the problem, it presents part of the photographic survey conducted in November 2007 with the conditions of the most critical slopes. There is in the pictures that the side slopes to the highway were in the process of degradation and (or) progressive destabilization requiring urgent interventions aimed at mitigating the ongoing problems. In terms of geometry, the slope had heights up to approximately 35 m. To determine the parameters necessary to verify the stability of embankments using three undeformed blocks corresponding soil to cuts 25 and 31. Samples of identifications are presented and the summary of the results of geotechnical tests performed and certain parameters. In laboratory tests, it was found that the strength parameters (cohesion and angle of friction) diverged somewhat from the usual laboratory parameters obtained in soils. This behavior was due to the fact that the heterogeneity of the samples for the presence mainly of discontinuities in the collected blocks. Before the run stability analysis and field surveys, it was found, the need for actions aimed at solving problems for marginal slope to the highway. Thus, due to the proximity of the intense rainy season, it was proposed the reconstruction of slope with surface protection of them aimed at stabilization and protection against erosion, as well as the execution of superficial and deep drainage. Aiming to further verify the possible degradation of the slopes by rain, was sought in INMET’s website (National Institute of Meteorology) precipitation to the region. It was found that for the time in January, February and March rainfall is considerably high, which could further compromise the integrity of the executed cuts. Faced with this possibility, he indicated consider the emergency actions that could prevent this degradation. Actions such as the reduction and protection of embankments shown in the study.