Rock Fill Research Articles

Evaluating the effectiveness of rolling impact compaction at a brownfield site with high and low frequency seismic surface waves and geotechnical testing

ABSTRACTUsing a case study from a brownfield site in Australia that contained substantial uncontrolled crushed rock fill, we demonstrate that innovative geophysics and ground improvement using rolling dynamic compaction can provide alternatives to costly excavation, removal and re‐engineering of soils. This approach can also overcome some of the limitations of conventional geotechnical testing in such conditions. The process we have developed involves selection and levelling of trial areas within larger brownfield sites. These are initially screened with electromagnetic geophysics to target environmental sampling sites, buried objects and local areas of potentially unsuitable or contaminated soils for removal and replacement. High and low frequency surface wave testing is then completed along closely spaced lines within the trial areas using specially adapted Multi‐channel Analysis of Surface Waves (MASW) methods and a modified land streamer. This provides S‐wave velocity distributions within fill and deeper materials over two depth ranges, at high vertical resolution from approximately 0 to 2 m and at lower resolution from 2 to ~10 m. These results are compared with geotechnical engineering test information. Ground improvement works are then undertaken using rolling dynamic compaction with a ‘square’ impact roller.Within this brownfield trial area, geotechnical testing showed that post‐compaction in‐situ densities increased by about 6 to 10%, while S‐wave velocities increased by up to 40%. This clearly demonstrates the sensitivity of S‐wave velocities to soil and fill modulus. The S‐wave velocity sections also showed the consistency of the landform created by impact rolling and that both high and low frequency MASW testing is needed for more accurate assessment of the densification of both shallow and deeper fill. Normalized S‐wave velocity difference sections and Cone Penetrometer Testing (CPT) provided a clear indication of the depth of influence of the impact rolling.A relationship was developed between post‐compaction S‐wave velocity and Dry Density Ratio (DDR) that formed the basis of a viable geotechnical verification strategy for the ground improvement works on the larger brownfield site. Electromagnetic and advanced surface wave geophysics, combined with innovative ground improvement methods by rolling dynamic compaction, represent an advance over current practice for brownfield site development.

On the deep structure of the North Sikhote-Alin and North Sakhalin fold structures junction area

A gravity field interpretation is performed for the North Sikhote-Alin and North Sakhalin fold structures junction area using the COSCAD-3D software package, and petrodensity and petromagnetic maps are compiled, thus making it possible to obtain new data on the petrophysical features and the deep structure of the area under study. As a result of the complex geophysical and petrophysical data’s interpretation, a sketch map of the disjunctive tectonics is compiled and the circular structure featuring a unique rock fill caused by the influence exerted by the mantle’s deep structure is identified and can be considered as a magma chamber structure with the center being in the North Sakhalin Bay.

Probabilistic Assessment for Seismic Performance of Pile-Supported Wharves

The main objective of this study is to investigate the influence of uncertainties associated with the material properties on the seismic performance of pile-supported wharves. For this purpose a two-dimensional finite difference model, representing typical pile-supported wharf structures from western United States has been constructed using software FLAC2D. Incremental dynamic analysis has been applied to evaluate the response of wharf structure under different levels of seismic loading. The uncertainties at both structural and geotechnical parameters have been investigated using a tornado diagram and a Wrst-Order Second-Moment (FOSM) analysis. It has been found that the uncertainties at the dead load of structure, friction angle of rock fill and the porosity of rock fill contribute most to the variability of the displacement ductility factor of the pile- supported wharf structures. Based on the results, design considerations have been provided.

Seepage Phenomenon for Wadi Megenin Dam

Most of the recorded dam failures in different parts of the world were related to seepage problems. Avoiding earth dam's failure due to seepage usually requires evaluating settlement, and piping, through field monitoring. The problem of dam seepage was experienced in The 38 m high rock fill Megenin dam is a at located at Souk AL khamis area 75 Km south of Tripoli. The dam was constructed in 1972, for two main purposes; to provide flood controls of the downstream areas, the cultivated fields and Tripoli city, and also provides water for irrigation purpose . The rock-fill dam was supported with an upstream reinforced concrete membrane on the upstreamface consisted of a number of concrete panels, linked together with central rubber water stops, and surface-sealed with a bituminous sealant. A concrete cut-off wall and grout curtain were constructed below the dam body to prevent reservoir seepage through the foundation. It was observed during the 3rd filling of the reservoir at the reservoir storage water level at +271.86 m on 15thMay 2003, seepage occurred at the wadi bed downstream of the main dam. The seepage occurred at a piezometric water level higher than the previously measurements during the period of 1973 to 1974. Seepage problem was also encountered in previous reservoir operation. To assess the seepage phenomena and it's impact on the dam safety, a study was carreied out through appliaction of t ground penetrating radar survey (GPR), piezometric analysis, and temperature field evaluation techniques as well as the construction of a flow net model for the dam. The results of the study showed that: the GPR profiles have delineated the critical zones in the dam body ,identify the water seepage paths from the reservoir to the down stream side of the dam, estimated the seepage rate through the dam foundation as 0.08 Ɩliter / ssecond and suggested measures to avoid problem that may occur in the future in Megenin dam due to seepage problems The study revealed the needs to design and implement effective monitoring program ,establish surface water gauging for any sudden increase in the seepage discharge in bed wadi at downstream , groundwater water levels fluctuation in the observation and seepage water beyond the dam. Maintain the upstream concrete facing joints and in case of alert condition occurred undertake additional raw of grouting curtain along the full length of the dam to protect dam foundation from flow.

Numerical Simulation of Stress Wave Propagation Induced by Cut Blasting in Multi-Media

Explosive blasting in rock and other media could induce strong shock wave. Near blasting zone, the blasting energy mainly break rock. Slightly far away from borehole, the blasting energy induces plastic damage. Farther afield, this kind of energy presents elastic deformation. In cut blasting, multi-boreholes initiate at the same time, multi-column stress waves occur superimpose and converge. Especially in multi-media, this process is extremely complex. Adopt numerical simulation method, set up multi-media model, which include weathered rock, highly weathered rock and plain fill. This paper simulated the propagation process of stress wave in these medias. Revealed the propagation mechanics of stress wave.

Ground Support Strategies at the Turquoise Ridge Joint Venture, Nevada

Weak rock masses of high grade Carlin-trend gold mineralization are encountered in the Turquoise Ridge Joint Venture underground mine. The sediments consist of very weak and altered limestone, mudstone, and carbon-rich clays. The rock mass ratings are described as very poor to poor (Bieniawski in Proceedings of the symposium on exploration for rock engineering, Johannesburg, South Africa, pp. 97–106, 1976). The undercut and fill or boxes stoping mining methods are used because of the low dipping ore body geometry, complex geology, and weak rock mass. Design criteria are chosen to keep openings in weak rock as small as possible to prevent unraveling and to minimize supplementary support. Typical ground support for drifting includes the use of bolts, mesh, spiling, and shotcrete. Quality control of cemented rock fill (CRF) through sampling and aggregate sieve testing is necessary to insure high support strength. Specific support may include shotcrete arches with steel ring sets and CRF “arches” as a replacement of weak rock masses around long-term mine openings. Movement monitoring is utilized in problem areas and is needed to quantify and validate computer modeling.

Design and Application of Concrete Faced Rock-Fill Dam Numerical Simulation Analysis Program

Reviewed the various constitutive mode of concrete faced rock-fill dam. Basis on the complex physical characteristic of filled the material and the framework of dam, a method of computer is given, introduced into the program of the concrete face rock-fill dam calculation with FORTRAN language on the ANSYS software. It is used to simulate two and three-dimensional nonlinear computation and compute figure simulation in the construction procedure and operation period for the concrete face rock fill dam, the result was intuitionist clarity.

Effects of loading rate and initial stress state on stress–strain behavior of rock fill materials under monotonic and cyclic loading conditions

This paper studies loading rate effect on stress–strain behaviors of high compacted rockfill materials. The large scale triaxial-dynamic equipment was used for this propose. To check the equipment capabilities, tests have been carried out on elastic spring and damping rubber specimens. The laboratory tests results indicate that the loading rate effect in elastic metal spring is negligible, while it has considerable effects on stress–strain behaviors in damping rubber, and especially in rockfill materials. The laboratory test results on rockfill materials have shown that dry specimens have higher E and D values compared to the saturated samples. Anisotropic specimens have higher Young’s modulus and less damping ratio in comparison to isotropic samples. Generally, the influence of the main parameters on E and D in rockfill specimens is initial vertical effective stress and loading frequency, respectively. The high compacted rockfill specimen exhibits a non-destructive response to the application of cyclic loading below a threshold axial strain level of <0.005%. Since the frequency effect was observed in the strain levels lower than 0.005%, and there is not meaningful build up of pore pressure in this strain level, therefore any effect of excess pore water pressure on the frequency effect is negligible.

IMPACT OF THE ATATÜRK DAM LAKE ON AGRO-METEOROLOGICAL ASPECTS OF THE SOUTHEASTERN ANATOLIA REGION USING REMOTE SENSING AND GIS ANALYSIS

Abstract. The Atatürk Dam is the fourth largest clay-cored rock fill dam in the world. It was constructed on the Euphrates River located in semi-arid Southeastern Turkey in the 1980s as the central component of a large-scale regional development project for the Southeastern Anatolia region (referred to as GAP). The construction began in 1983 and was completed in 1990. The dam and the hydroelectric power plant, which went into service after filling up the reservoir was accomplished in 1992. The Atatürk Dam, which has a height of 169 m, a total storage capacity of 48.7 million m3, and a surface area of about 817 km2 plays an important role in the development of Turkey's energy and agriculture sectors. In this study, the spatial and temporal impacts of the Atatürk Dam on agro-meteorological aspects of the Southeastern Anatolia region have been investigated. Change detection and environmental impacts due to water-reserve changes in Atatürk Dam Lake have been determined and evaluated using multi-temporal Landsat satellite imageries and meteorological datasets within a period of 1984 to 2011. These time series have been evaluated for three time periods. Dam construction period constitutes the first part of the study. Land cover/use changes especially on agricultural fields under the Atatürk Dam Lake and its vicinity have been identified between the periods of 1984 to 1992. The second period comprises the 10-year period after the completion of filling up the reservoir in 1992. At this period, Landsat and meteorological time-series analyses are examined to assess the impact of the Atatürk Dam Lake on selected irrigated agricultural areas. For the last 9-year period from 2002 to 2011, the relationships between seasonal water-reserve changes and irrigated plains under changing climatic factors primarily driving vegetation activity (monthly, seasonal, and annual fluctuations of rainfall rate, air temperature, humidity) on the watershed have been investigated using a 30-year meteorological time series. For all images, geometric corrections including digital elevation information and Tasseled Cap transformations were carried out to attain changes in surface reflectance and denoting disturbance of Landsat reflectance data. Consequently, thematic maps of the affected areas were created by using appropriate visualization and classification techniques in conjunction with geographical information system. The resulting dataset was used in a linear trend analysis to characterize spatiotemporal patterns of vegetation-cover development. Analysis has been conducted in ecological units that have been determined by climate and land cover/use. Based on the results of the trend analysis and the primary factor analysis, selected parts of South-eastern Anatolia region are analyzed. The results showed that approximately 368 km2 of agricultural fields have been affected because of inundation due to the Atatürk Dam Lake. However, irrigated agricultural fields have been increased by 56.3% of the total area (1552 km2 of 2756km2) on Harran Plain within the period of 1984 – 2011. This study presents an effective method for time-series analysis that can be used to regularly monitor irrigated fields in the Southeastern Anatolia region.

Spanish technical regulation for road construction

Abstract The new Technical Regulation for Road Construction (PG3) has applied in Spain since 2002 and governs execution of all the highways, expressways and motorways run by State Administration. The most important aspects introduced in this regulation in terms of the construction of fills are (1) extending the characteristics of the fill material to use as large a quantity as possible of the excavated ground in situ and to keep the amount sent to dump sites to a minimum; (2) to set up standards to regulate finished fills; and (3) to define a new type of random or quarry-run fill consisting of materials with a grading between earth and rock fill that were not in the earlier PG3 regulation. The new PG3 regulation refers to the construction of earth, rock and random fills, and pays particular attention to the placement, installation and the relevant control of the methods involved. In the case of earth fills, the control method involves fixing some preliminary characteristics for the soils to be used in fills, determined by laboratory tests, whereas for random and rock fills, the control consists of first creating test fills through which the previously established compaction procedure is accepted or modified. For random and rock fills, the control of the finished fill requires dividing the layers into set-sized sections and running tests on predetermined strips. The regulation also defines the criterion for acceptance or rejection of the zone being tested.

Czech standards and specification for earthworks

Abstract General requirements for earthworks in the Czech Republic are given in the national standard CSN 73 3050 ‘ Earthworks ’ which has been in place since 1987. It provides information on excavation including the rather controversial seven excavatability classes, recommendation for slope and shoring of excavation, requirements for fill construction, control of compaction and tolerances of finished surfaces. CSN 73 6133 ‘ Design and execution of earth structures on roads ’ is currently being revised. Beside classical soil and rock fills it gives recommendations for the use of difficult or marginal materials such as uniform (wind drifted) sand, loess, colliery spoil, fly ash, slag. Control of earthworks is described in CSN 72 1006 ‘ Compaction control of soils and other fills ’ which is valid for both highway and railway infrastructure as well as for buildings, landfills etc. Apart from national standards, the Ministry of Transport supports publications of technical specifications for design (TP) and construction control (TKP) focused on certain material or technology used in highway and railway infrastructure. TP coversfor example soil improvement, soil reinforcement, use of fly ash, colliery spoil or lightweight fill. TKP givesfor example detailed requirements for the site quality control of earthworks, reinforced fill, soil nailed slopes and gabions.

Prediction of Concrete Faced Rock Fill Dams Settlements Using Genetic Programming Algorithm

In the present study a Genetic Programing model (GP) proposed for the prediction of relative crest settlement of concrete faced rock fill dams. To this end information of 30 large dams constructed in seven countries across the world is gathered with their reported settlements. The results showed that the GP model is able to estimate the dam settlement properly based on four properties, void ratio of dam’s body (e), height (H), vertical deformation modulus (Ev) and shape factor (Sc) of the dam. For verification of the model applicability, obtained results compared with other research methods such as Clements’s formula and the finite element model. The comparison showed that in all cases the GP model led to be more accurate than those of performed in literature. Also a proper compatibility between the GP model and the finite element model was perceived.

Primary Engineering Geological for Shuibuya Underground Power Station and their Treatment

The Shuibuya hydropower station is located in Badong County in the middle reach of Qingjiang River. It is the first cascaded project in Qingjiang mainstream. The Project consists of a concrete faced rock fill dam (CFRD), underground power house, chute spillway on the left bank, and the sluice tunnel on the right bank. The dam is 233m high, which is the highest of its kind in the world at present. The installed capacity and annual output of Shuibuya Power Plant are 4×460MW and 3.92 GWh respectively. The rock mass of foundation of Shuibuya project is a type of stratified sedimentation rock mass is composed of interbedded stratum by weak layers and hard layers. To solve engineering geological problem is difficult and challenging. For example, the intake slope of Shuibuya hydropower diversion tunnel was a landslide, and diversion tunnel outlet is located at the toe of Maya slope with 360m high, rock mass of the underground powerhouse caverns are soft and hard rock inter-layered, with multi-structural planes, multi-shear zones, and the lithology of rock is highly krast. Some researchs and geological treatments were performed during the geological exploitation and construction, which is fundamental and primary.

Study on Settlement of High Fill Embankments on Rock Slope under Complicated Stress Conditions

Compared with general roadbed，high fill embankment has the characteristics such as higher height， larger cumulate settlement and it’s stability should be technical analyzed. High fill embankment is one of the most important projects in highway engineering. The settlement in highway construction, especially the differential settlements, may lead to the cleft and stagger of pavement，and largely affect the quality of driving as well as the operational life span. So how to reduce the settlement and get rid of the danger made by the settlement has been an important subject in highway construction field and the research has important reality significance. Therefore, in order to master the deformation law of high fill embankment on rock slope under complicated stress conditions, systems of monitoring network are established to monitor the settlement of high embankment with strong weathering filling, high embankment on rock slop and high rock fill abrupt slope embankment respectively. Through analysis of settlement of high fill embankment stability under complicated stress conditions, conclusions are made in details.

Study on Seismic Permanent Deformation of Earth Rock Fill Dam

For the flaw of safety evaluation system using safety factor as control index, seismic permanent deformation is used to evaluate the safety of earth rock fill dam. In this study, the seismic deformation of Zipingpu dam after Wenchuan earthquake is measured and analysis. The deformation in the middle of the riverbed on the crest is the largest. The deformation in the left dam abutment is smaller than that in the right. The seismic permanent deformation on the crest grows rapidly in the first three days, and then develops slowly. The results show that deformation grows along the height of dam with the relation of exponential or power function.

Study on Application of Extrusion Concrete Side Wall in Concrete Face Rock Fill Dam

Compared with the traditional upstream dam slope construction method, the extrusion side wall technology has many advantages. such as less process steps, little interference, quick construction speed etc ,So it arouse more and more attention in the engineer design and construction fields . The technology of extrusion concrete side wall applied to the construction of concrete face rockfill dam in the Bailian river storage power station, machinery and equipment were used on the cushion material to form a concrete wall extrusion , which avoid the traditional process of Ultra-filled cushion material, rolling slopes, cut slopes and other complicated process, not only ensure the quality, but also improve the stress state of the panel.

凍結融解作用を受ける岩石の破壊プロセスと耐久性の評価

Durability evaluation of rocks subjected to freezing-and-thawing is important for stability assessment of a rock fill dam as well as rock slopes, especially in cold weather regions. In this study, freezing-and-thawing tests up to 300 cycles were carried out on twelve kinds of rock samples in order to characterize fracture propagation by freezing-and-thawing and evaluate the durability, and fracture propagation was observed. The fracturing process was characterized by macroscopic observation by digital camera and changes in physical properties. Fracture initiation and propagation in the specimen were also observed by using X-ray CT. It was found that the fracturing process depends on the rock type. For rocks which possess preferred orientation of pre-existing fractures and anisotropy of tensile strength, only one fracture propagated dominantly and split the rock sample in half. On the other hand, for isotropic rock, propagation of several fractures occurred and rock samples were split into several parts. Additionally, spalling continuously progressed once the loss of weight exceeded 5% for isotropic rocks because fractures had developed throughout the specimen. This result indicates that freezing-and-thawing cycles at 5% weight loss is assumed to be the spalling initiation. Therefore, we can conclude that the number of freezing-and-thawing cycles to the spalling initiation is the important indicator of the durability evaluation. It was also pointed out that both supply capacity of water to the crack tip and crack growth resistance affect the durability, because the tensile strength divided by the percentage of water absorption is in good correlation with the number of cycles to the spalling initiation. It is concluded that the durability can be easily evaluated by both tensile strength and the percentage of water absorption.

Analysis of dam deformation measurements with the robust and non-robust methods

Rapid developments in engineering structures and the growing interest in studying the earth crust movements, the analysis of deformation measurements, measurement methods and precision has revealed new demands. The purpose of this study is to determine the deformations that take place on dam crest due to different water level, water load and dam’s body weight. AltA±nkaya Dam, which is a rock fill dam, was selected as application area and a deformation network consisting of 6 reference and 11 object points was constructed. In this study, deformation measurements were performed between 2000 and 2002. Measurements were made every June and September in that the water level was minimum and maximum, respectively. Hence, measurements were made in 4 periods. All measurements were performed using static GPS measurement method. In this study, Iterative weighted transformation (IWST), Least Absolute Sum (LAS), Congruency test analysis method and Fredericton was used for performing two dimensional deformation analyses. Key words: GPS, dam, deformation, analysis, congruency test, IWST, LAS, Fredericton.

Analysis of Non-Darcy Flow in Rock Fill Materials Using Gradually Varied Flow Method

Analysis of flow through rockfill materials is usually carried out by solving the differential equation which is a combination of nonlinear [i=mvn] and continuity equations. However, solving this differential equation either by means of finite difference method or similar procedures is relatively time consuming, and with uncertainty involved in water surface profile this becomes even more difficult. To analyze flow through rockfill materials an alternative method which is based on gradually varied flow theory may be applied that is comparatively simpler and less time consuming. To apply this alternative method it is necessary to examine the validity of assumptions on which gradually varied flow method are based. Moreover, the involved parameters in gradually varied flow equation should be reverted to porous media condition. In this research by conducting a vast number of experiments on various types of materials the acceptability of assumptions of gradually varied flow method for analysis of flow through coarse porous media is investigated and the effect of physical characters of porous medium such as void ratio, uniformity coefficient Cu, gradation coefficient Cc and viscosity of fluid as well as certain features of flow such as velocity and hydraulic gradient are also examined. Findings indicate that: 1). by accepting some degrees of discrepancies, one may use the gradually varied flow method for analysis of flow through coarse porous media. 2). the permeability parameters of coarse porous media may be successfully related to the physical characters of granular materials. 3). A Comparison between observed and computed flow profiles through media indicates accuracy and applicability of equations that are derived by authors of this paper.

In situ Experiment on the Improvement of Rock Masses Deformability by Grouting in Yamaguchi Regulating Reservoir (Rock Fill Type Dam)

In situ Experiment on the Improvement of Rock Masses Deformability by Grouting in Yamaguchi Regulating Reservoir (Rock Fill Type Dam)