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In this study, the settlement problem in Ilgın district, which has high groundwater level at the northwest of Konya and is widely clay, is investigated. In order to determine the settlement characteristics of the investigated area, a research pit was opened at different points and drilling and UD samples were taken. Experiments were conducted on these soil samples. The compaction index (Cc), the compaction index (Cr), the consolidation coefficient (Cv) and the consolidation settlement were calculated according to the results of the consolidation test applied to the samples consisting mostly of clay and thin soil materials. As a result, it was determined that the ground water level and the consolidation of soils were effective in the deformations observed in the buildings in Ilgın settlement area.

The present study was performed in order to determine the engineering geology and geotechnical details of soils and rocks along Tabriz Metro Line 2(TML2) by using the information and raw data which were acquired by borehole drilling and all field and laboratory tests in the study area. The minimum and maximum depths of the boreholes were 15 and 40 m, respectively. The results of their analysis revealed that geologically, the areas of metro route, mainly formed by alternating layers of claystone, siltstone, marl, and conglomerate, covered mainly by the alluvial deposits and in addition to older, dextral, strike-slip North Tabriz Fault (NTF) which is a major and most important geological structure of Tabriz area, there are also many minor and generally young and seismically active faults. The results of investigation on the groundwater depth in boreholes of TML2 also indicated that the groundwater depth varies between 1.5 and 30 m, along the route of metro. Eventually, based on the standard penetration test values (N-SPT), it was revealed that soils of the western parts of TML2 are in the group of dense to very dense, the central parts are in the group of very dense (Bazaar area) and dense (Fahmideh area), and the eastern parts are very dense. And finally the results achieved from determining groundwater sulfate values according to Concrete Code of Iran (CCI) indicated that the amount of soluble sulfate in the soil is mild to extremely high. Accordingly, the amount of sulfate increases from the western to the eastern parts. So that, this value is between 200 and 26,500 ppm. Based on these studies, the average of sulfate in the western, central and eastern parts is, respectively, 1118, 1275 and 4840 ppm. Thus, the groundwater in the east part is highly aggressive, and deterioration of concrete lining of the tunnel is expected in the near future.

Embankment structures are important to protect against flooding damage. Suffusion, in which fine particles within the soil are transported and washed away following the seepage flow, intensifies the instability of embankment structures. Therefore, it is possible that some embankment structures that repeatedly experienced flooding and rainfall penetration have been deteriorated. However, there is little research investigating the relation between seepage flow histories and deterioration within the embankments. In this study, small-scale modeling tests duplicating a river levee were conducted under different seepage flow histories: (i) short term-critical ground water level, (ii) continuous-high ground water level and (iii) repeatedhigh ground water level. The work in this paper investigates changes in “drainage flow rate”, “height of ground water level” and “particle size distribution” during the seepage tests, and evaluates the effects of seepage flow histories on them. Soils gradually showed lower permeability under the first seepage experience in each cases. In the case of relatively longer flooding duration, the drainage flow rate is gradually increased. Fine particles were eroded, regardless of the seepage flow histories; “the number of fluctuations” and “height” of ground water level could particularly be a trigger of suffusion.

Slope is (part of) the side of a hill or mountain. Slope stability became the main concern while working on a construction project, especially on road/highway project. Slope stability determined by soil parameters which include: physical & mechanical behavior of the soil, ground water level, rock mass structure, etc. Because there is an uncertainty on parameters value in the slope design, causing the slope vulnerable, it needs a concept such as probability analysis to find the stability of the slope. Probability analysis using Monte Carlo method involved a few parameters such as unit weight, cohesion and friction angle. Soil and Slope Geometry data were obtain from prior research. In this analysis there are three trials conducted with various slope angle along with similar material. The result will show a safety factor and failure probability percentage. From this analysis, it can be concluded that the steeper the slope, the lower safety factor number will be shown. The contrary result applied on probability of failure, the steeper the slope, the bigger probability of failure for soil material will occur.

The paper deals with strengthening structures against punching shear with focus on strengthening of existing concrete foundation slabs. These can be slabs of basements of residential, administrative and other buildings. Also, foundations slabs placed on piles can be considered. This is very specific case of strengthening where only one surface of the structure is accessible. Strengthening is often designed using massive new bearing elements, which are space-demanding. Attention is paid to the development of technology that minimizes the resulting constraints on the surrounding area and is sufficiently effective. Inspiration is strengthening of ceiling flat slabs with additional shear reinforcement. Compared to the ceiling slabs, a larger load must be bear to the foundation structures and therefore the shear reinforcements demand larger dimensions. Mechanical expanded anchors are used for anchoring on the inaccessible side. A significant contribution of mechanical anchoring is demonstrated in the tests results which make possible more efficient design of additional punching reinforcement.

The article deals with the effect the geological engineering conditions have on the behaviour of structures under conditions of North-Western soft soils. A structural survey conducted at an oil refinery in the Leningrad region showed numerous faults and damages caused by settlements of the bearing structures and their foundations. Traces of leakages on the retaining walls of the pumphouse as well as next to the pipeline inlets witness a man-triggered raise of the ground water level. Crack formation in bottoms and walls of the aerotanks and sludge tanks was also denoted. It might be caused by the reduction of foundation soil bearing capacity. In its turn, deterioration of physical and mechanical features of the foundation soil is linked to the change in the hydrological regime of the area, which is proved by rich seepage of ground waters through the cracks in tanks. Having analyzed the structural and geological engineering conditions the authors recommend elaborating and performing a project to restore the proper working order of structures.

Large number of rain-induced landslides occurred on 16 September 2011 in Nanjiang, southwest of China. The typical depth of failure surface was from 1 to 5 m at the gently inclined interface between the superficial red silty clay and bedrock. In order to explain the failure characteristics of these shallow landslides, we conducted a rainfall infiltration simulation test, calculated rainfall infiltration depth using modified Green-Ampt (G-A) infiltration model as well as considered the atmospheric effects on the slope failures. Results show that the permeability of red clay is extremely low and the rainfall infiltration depth is limited to around 0.5 m during a rainstorm. The rainfall infiltration capacity can be enhanced within the depth of atmospheric influence, which is determined as 5.4 m in the study area. With the increase of soil depth and the lower degree of weathering, the void ratio and permeability are gradually reduced; thus, the rainfall infiltration continues following a decreasing trend until the bedrock is reached. Within the shallow landslides in the study area, under the condition of rainfall, the slope can keep in a stable state when the depth of wetting front is less than the thickness of soil layer. When the wetting front proceeds to the interface between the silty clay and bedrock, the potential slip surface can develop on such soil-bedrock interface, in relation to the increased pore water pressure and ground water level. Consequently, shallow failures will occur along the soil-bedrock interface in a depth of 1–5 m.

A weak form quadrature element formulation is proposed for coupled analysis of unsaturated soils. In the formulation, integration points are coincident with nodes where all variables are obtained so that numerical implementation is made easy. Accuracy can be improved by the increase of the approximation order. An elasto-plastic constitutive model is used for description of the mechanical behavior, and hydraulic hysteresis of the soil water characteristic curve is considered. Results are compared with available analytical solutions, experimental data and numerical solutions in the literature, and good agreement is reached. Rapid convergence is reached as compared with the conventional finite element method. The effect of the ground water level is discussed.

Prambanan Temple is a cultural heritage located in Jogjakarta. Tectonically, the Special Region of Jogjakarta and its surroundings are an area with a fairly high level of seismic activity in Indonesia. Geotechnically, the soil in Jogjakarta is sandy with similar gradation. The thickness of the sand ranges from -50 m to -60 m. Whereas, the ground water level is located at a depth of -12 m during dry season and in rainy season, it rises from -6 m to -4 m. The impact of soil types and the high Ground Water Level (GWL) allow it for liquidation to occur during an earthquake. This study was conducted using liquefaction analysis, through Liquefaction Potential Index (LPI) method with ground water level variations. Before analyzing the liquefaction using LPI method, Peak Ground Acceleration (PGA) methods were used, and analysis could then be done through Cyclic Resistance Ratio (CRR) and Cyclic Stress Ratio (CSR) to obtain safety factors and the Liquefaction Potential Index analysis was then conducted. To analyze this liquefaction, earthquake data from 2004 to 2019 and the results of the SPT field test at the Prambanan Temple were needed. From the liquefaction potential analysis through Liquefaction Potential Index (LPI), the results showed that in CSR Seed & Idriss (1971) and CRR Tokimatsu & Yoshimi (1983), GWL 1 m at depths from 4.5 m and above, the potential of liquefaction occurrence was high. The largest PGA value was obtained based on the Matsuchka (1980) method on May 26, 2006 which was 0.102.

The paper presents stability and seepage analysis performed in unsaturated regime to take care of the infiltration through the dam. Seepage analysis is divided into two stages: steady state analysis and transient analysis. It will be determined the pore water pressure load, the ground water level, estimate the flow (path and quantity) and also, an advanced analysis considering rainfall and rapid drawdown. Van Genuchten model will be used for the unsaturated soil.

Recently, due to the expansion of urban infrastructure for the citizen convenience, the shield tunnel construction has increased considering the civil complaints minimization and construction stability. Most shield tunnels are designed based on the assumption of the undrained condition that underground water does not inflow, but they are operated in the field as drained tunnels with drainage facility to drain underground water. Therefore, the drained condition needs to be considered in the shield tunnel design. It is also necessary to consider the weathered granite soil that is widely distributed throughout the country and consequently is encountered in most of construction sites. In this paper, the model test which can control total stress and pore water pressure and simulate the underground tunnel located in the weathered granite soil below ground water level is conducted. Total stress, pore water pressure and an inflow water into an inner pipe were measured using the testing device. Test results showed that the total stress in a drained condition was lower than in an undrained condition because pore water pressure decreased in a drained condition and an inflow water into an inner pipe was proportional to the loading stress in a drained condition. As a result, if a drained condition is considered in the shield tunnel design, the more economical design can be expected because of the stress reduction of the lining.

Unlike the primary consolidation settlement, the settlement of ground water lowering is not considered separately because of relatively small residual settlement. But the allowed residual settlement (30 mm) of the concrete track in the high-speed railway may be exceeded due to unexpected excessive ground water lowering. This study analyzed the effect of the settlement according to the ground water level change using finite element analysis of stress-pore pressure coupling model, and compared the analysis results with the measured data. As a result, the range of elasticity modulus satisfying the allowable settlement was proposed, and it is suggested that settlement due to ground water level changes should be reflected in the design.

Vacuum preloading is a commonly-used method to improve a large area consisting of soft soil. However, most theoretical and experimental studies have not considered the water table charge during vacuum preloading. This paper analyzed the changes of excess pore water pressure and groundwater table during the process of vacuum preloading, and confirmed that the groundwater table varied during vacuum preloading and had influence on the consolidation process. Based on the field observation, an analytical solution to calculate the consolidation degree of soil by vacuum preloading considering the groundwater table change was developed. Then a parametric study was conducted to investigate the influence factors of the drain spacing ratio, depth of ground water level, soil permeability coefficient ratio of undisturbed area and disturbed area on the consolidation. The developed solution is valuable for the prediction of consolidation degree under vacuum preloading in practice.

Two 500 m deep investigation shafts were excavating in the granite body in Mizunami, central Japan by JAEA (Japan Nuclear Cycle Development Institute) in 2004-2012. Groundwater with volume of 700 m3 was generally pumping a day to prevent the shafts from submerging in 2012 following the excavating. As a result of pumping the groundwater, the ground water level lowered to 60 m in the borehole with the distance of 200 m from the excavating shafts in 2012. Leveling network extending 2 km × 2 km around the shafts was established to detect the vertical deformation around the shafts in 2004, and precise leveling was done every year. An 18 mm ground subsidence was detected in the benchmark close to the shafts for 8 years in 2004-2012, and time series of subsidence at benchmark was consistent with the groundwater drawdown. The groundwater drawdown and ground subsidence were caused by the pumping ground water in excavating shafts.

Groundwater levels in embankments often rise due to heavy rainfall, which can occasionally cause embankments to collapse. In order to decrease the ground water level, it is important to take countermeasures to drain the water from areas in embankments which could weaken in heavy rain. The drain pipe method for embankments has been adopted widely by Japanese railways as a water draining method. However, installation specifications for drain pipes have not yet been established, and the finer details of construction work currently depend on experience. This study therefore set out to evaluate the effect of drain pipes quantitatively, with a view to proposing a set of installation specifications for drain pipes in embankments, based on the evaluation and considering the height of the embankment, external permeance, inter alia.

Summary The termination of industrial activities may have side effects with harmful impact on civil infrastructure. The drastic increase of ground water level may endanger the quality of the fresh water resources and the basement stabilities of the surface infrastructures. Geoelecric survey is an effective method in solving environmental or geotechnical problems in urban areas. This study introduces two case histories on geophysical characterization of sites that are endangered with the reappearance of karstic water. Validated with drill hole data the subsurface structures were reliably imaged. Extended with laboratory analysis of water and mud samples the source of water contamination was identified. The successful designation of subsurface aquifers and flow directions gave useful information for mitigation planning.

Fur die Grundung einer Dungemittelanlage in Port Neal/Iowa wurden durch den Bauherrn Schneckenbohrpfahle (sog. ACIP-Piles) als Grundungsentwurf vorgegeben. Angesichts der bis in grose Tiefen unterhalb des Grundwassers anstehenden, sehr enggestuften, feinkornigen Sande wurde die Ausfuhrung im Hinblick auf DIN EN 1536 als kritisch eingestuft. Im Rahmen von umfangreichen Pfahlprobebelastungen konnte jedoch zunachst gezeigt werden, dass bei ausreichender Qualitatssicherung Schneckenbohrpfahle auch bei ungunstigen Baugrundverhaltnissen ordnungsgemas hergestellt und gute Tragfahigkeiten erzielt werden konnen. Im Rahmen der Ausfuhrung der Bauwerkspfahle sind jedoch erhebliche Schaden aufgetreten, da die Bohrschnecke auf einer Tonschicht hoherer Konsistenz aufsas und Boden in nennenswertem Umfang gefordert wurde. Zuruckzufuhren sind die Schaden neben den ungunstigen geologischen Randbedingungen auf einen Wechsel des ausfuhrenden Spezialtiefbauunternehmens, welches die nach DIN EN 1536 geforderte ortliche Erfahrung nicht uber Probepfahle nachgewiesen hat. Zudem wurden im vorliegenden Fall die Schaden durch die eingesetzte Maschinentechnik des Drehbohrgerats begunstigt, welche sich in den USA von der in Europa verwendeten Technik unterscheidet. Application and limitation of auger-cast-in-place (ACIP-) Piles – Experiences of an industrial project in Iowa/USA For an industrial complex in Port Neal/Iowa, auger-cast-in-place piles (ACIP-Piles) haven been chosen for the foundation structure. With reference to the purely graded sand deposits, which have been encountered to greater depth in conjunction with a high ground water level, the installation of such piles has to be critically expected with reference to DIN EN 1536. However, the installation technique as well as acceptable pile capacities could be verified in the course of extensive pile testing. Nevertheless, considerable damages occured during the installation of the working piles. The damages can partly be attributed to an interlayered very stiff to hard cohesive soil layer at a depth of app. 20 m, which couldn't be smoothly drilled and which led to a soil extraction in the vicinity of the pile shaft. Moreover, a new drilling company was commissioned for the installation of the working piles, whose specific experience with the chosen pile type was not directly verified before. Finally, the damages were benefit by the chosen drilling technique.

The main dam of Banqiao reservoir consists of the concrete overflow dam and the earth dam in both sides, which are connected by concrete lateral key wall. Field observation shows that serious leakage problems exist at the connection of the overflow dam and the earth dam in right bank. According to the real size of structures, the FEM model are established to calculate and analysis the seepage field characteristics at the connection part. The potential ground water level shows that the reservoir water flowing to the downstream bypassing and passing through the lateral key wall and the anti-seepage curtain. And there exists partial seepage passage at the connection part. As the contact seepage gradient along the lateral key wall is uneven, the contact leakage at the connection part is not fully safe although the average contact seepage gradient is within the permissible range. Effective measures should be taken to solve the seepage defects at the connection part.

The seepage field regulation is important for the stability canal liner plate and slope for along the Middle Route of the South-to-North Water Transfer Project, especially for stretches excavated in expensive soil area with groundwater level. In order to analyzing the rationality and efficiency of seepage regulation measures comprehensively, a typical section was modeled, and the seepage field was simulated with the 3D finite element technology. The distribution of seepage field was analyzed and the seepage control measures were compared. The results show that water pressure on the underside of canal pavement would be reduced significantly by the measures, such as the measure of drainage cushion with drainage holes which open just when ground water level is higher than the canal water level, the measure with drainage cushion replaced by the drainage board. The differences among the two kinds of measure were compared. Their application conditions were discussed and proposed.

The effect of embankments on the temperature regime of ground with continuous and discontinuous permafrost was simulated. Ground conditions are considered based on the example of the Zapolyarnoe field. The temperature dependences of the groundwater level and the capacity of the water-saturated embankment layer in the winter and summer were found. The most favorable conditions for irrigation of embankments for raising and lowering the ground temperature were ascertained.

In this study, numerical analyses and model tests were conducted to figure out the behavior of a slope reinforced by upward drainable soil nails during rainfall. The model tests were carried out on both reinforced and unreinforced slopes. To verify the results of the tests, seepage analyses were performed and compared with the test results using a commercial program, SEEP/W. The results showed that the numerical analyses have in overall a good agreement with the experiments in the variations of ground water level and pore water pressure even though there is some time delay for the experiment before the changes in the ground water level and pore water pressure after rainfall are observed, while the numerical analyses not.

The south Kalimantan Province has various soil characteristic, the difference of ground water level included . Experimental modeling of foot plate foundations in various ground water level is too difficult to be performed. There were so many variables that need to be evaluated in the modeling. The numerical model was based on finite element method such in Abaqus allowed the modeling of foot plate foundations with the various of ground water level. This study modeled the foot plate foundation structure where located on various ground water level by giving variations of the effect of water level to the elevation of the foundation. Water level variations are determined successively below the foundation elevation, the same as the foundation elevation and above the foundation elevation. The analysis performed is static structure analysis with idealization of 2D shell idealization. The result of the research showed that the ground water level effect the stress and deformation of soil closed to foundation elevation. The stress had been evaluated at the base of the foundation for each ground water level difference correspondently 16,53 MPa, 9.34 MPa and 3.59 MPa. The lowest stresses was occured in ground water elevation above the foundation elevation (78.28%).

The marine sedimentary strata are spread in coastal area of Tianjin. Due to low soil strength, high underground water level and strong soil plasticity flow, instability accidents happened frequently in soft soil area. In the foundation excavation of underground station, because of stress release and change in ground water level, the differential settlement of surrounding buildings, ground crack and deformation of underground pipeline will happen. The stability of surrounding rocks in the foundation excavation of underground station has been calculated and analyzed by using numerical simulation method. The Surrounding soil deformation of foundation pit has been gotten to analyze.

In the future, the more frequent occurrence of severe heat waves and long dry periods due to climate change can cause lowering of the ground water level and therefore consolidation of the soil. Consequently, increased differential settlements are expected that may damage underground water infrastructure. Models were developed to assess the impact of differential settlements on pipe failure. The main concept of these models is that the pipe-soil system is schematized as a beam on an elastic foundation using Winkler type springs. For climate change induced settling, a parametric function of the soil settlement is proposed. A Monte-Carlo analysis has been applied to predict pipe failure probabilities.

This paper reviews the analytical solutions for the impact of land reclamation on the ground water level and the saltwater interface with unconfined groundwater conditions in coastal aquifers. The applicability of the analytical solutions is somewhat limited by assumptions such as Dupuit-type flow and the Ghyben-Herzberg relation. Variable-density flow and solute transport simulations conducted by the numerical code FEFLOW were used to evaluate the accuracy of these analytical solutions. Three field-scale hypothetical cases were simulated for the numerical verification. The results show that a seepage face occurs in the numerical results rather than in the analytical solutions, but only minor difference occurs between the numerical and analytical solutions. This implies that the analytical solutions are reasonable despite the used assumptions.

PURPOSES: This study is to evaluate a ground water level effect on frost heaving in road pavements. METHODS: The effects of water table on frost heaving in pavement systems were evaluated from the mechanical analysis using FROST program. The input parameters and boundary conditions were determined by considering climates, pavement sections, and material properties specially subgrade soil types in Korea. RESULTS: When the water table located above the freezing depth, amount of frost heaving caused by freezing the water in pavement itself was big enough to damage in pavement system, although pavement system consists of fully non-frost-susceptible materials with sufficient thickness of anti-freezing layer. The amount of frost heaving was decreased rapidly with increasing the distance between the water table and freezing depth. CONCLUSIONS: It was concluded that there is no engineering problems related with frost heaving in practical sense when the distance between freezing depth and water table is over 1.5m for having subgrade soils less than 50% of #200 sieve passing to meet specification on quality control in Korea.

Previous research reported that the ground water in the backfill of reinforced soil wall made it deteriorate. According to the damage investigation of Great East Earthquake 2011, the reinforced soil structure due to high ground water level by seismic wave were deformed remarkably. Some of them classified ultimate limit state or restorability limit state. However, more than 90% of reinforced soil structure, which suffered from this earthquake, were classified into no damage condition. Therefore, it is necessary that the seismic behaviors of multi-anchor wall due to seepage flow should be clarified in order to adopt the performance-based design in such reinforced soil structure. In this study, a series of centrifugal shaking table tests were conducted to investigate the seismic behavior of multi-anchor wall due to high ground water level. The reinforced drainage pipes were installed into the backfill in order to verify the dewatering effect and additional reinforcement. Furthermore, to check only the dewate...

Ground subsidence is one of the main geological hazards in Shanghai. The ground subsidence is caused by pumping groundwater greatly. In the past, studies of ground subsidence in Shanghai were mostly taken for the ground subsidence caused by pumping confined water in Puxi. And ground subsidence caused by pumping phreatic water was rarely studied. Dewatering preloading is a new technology for soft soil treatment. The monitoring of ground water level, ground subsidence, pore water pressure in the process of dewatering preloading test for a soft soil treatment project in Pudong showed that pumping phreatic water can also cause ground subsidence. The ground subsidence caused by pumping phreatic water was analyzed in this paper. The relationship between phreatic water level and ground subsidence was obtained.

The change in strength and deformation behavior of a typical marine clay deposit formed under shallow water is presented and discussed for the conditions of changing water table. This is a costal marine clay deposit with moderate carbonates along the east coast of India. The soil samples were taken from tidal flats where the sea had receded some time back, and the behavior of this deposit had been studied for the conditions of 1976, with high water table, and for the conditions of 2001, with depleted water table. Undisturbed soil samples were taken from sheeted open test pits. Standard consolidation and triaxial shear tests were conducted. Consolidation tests conducted on the samples taken for 1976 conditions with high water contents indicate that cementation effect are erased out under moderate stresses. Beyond this stress range, it behaves like soft, normally consolidated clay. In contrast, the results obtained from samples taken during 2001, with depleted water table, clearly indicate that the soil beh...

Slope movements have caused severe damages of civil infrastructures and numerous human disasters. An early warning system (EWS) is demanding to predict the slope movement project. Time Domain Reflectometry (TDR) has been resort to monitor slope movement in a variety of geotechnical settings including highway cuts and rail beds. Until now, the interpretation of TDR results for detecting slope movement and identifying the location of shear planes has been limited to visual inspection of the plots of cable reflectance versus distance along the cable. Geotechnical applications of Time Domain Reflectometry (TDR) are continuing to develop and usage is increasing, particularly for monitoring subsidence over active and abandoned mines and monitoring slope movement. Assessing the stability of slopes is a difficult task that requires a strict approach. This paper starts by presenting a scope of slope movement factor such as soil water content, ground water level and ground movement. The physical and mechanical beha...

Kuwait City is a Middle Eastern coastal city characterized by arid conditions with shallow, saline groundwater. As some parts of the new ring road development were below the ground water level, 5,000 anchors were incorporated in the design to restrain the road against hydrostatic uplift pressures. About 750 anchors were only partially completed when they were inundated with aggressive groundwater for a period of about 2 years when dewatering was temporarily abandoned as a result of the Gulf War in 1990. Subsequently, physical, metallurgical and strength tests were undertaken to assess both the degree of corrosion and the long-term integrity of these partially completed anchors. The paper discusses the testing, the remedial measures and the long-term monitoring system. It was decided to keep some of the dewatering wells as a precautionary standby in case of future problems.

A series of centrifugal model tests was conducted to examine the long-term loads acting on a tunnel fixed in space in soft clay, experiencing long-term deformation. Two possible hydraulic boundary conditions were adopted in the experiments: ‘tunnel drainage condition’ where the tunnel lining acts as a drainage boundary, and ‘bottom drainage condition’ in which one-dimensional consolidation of the clay takes place due to lowering of the ground water level. The test results are compared in view of the mechanism of ground deformation around the tunnel and the variation of earth pressures on tunnel lining.

The region of Kochang(Chollabuk-Do) located in the west-southern area of the Korea and passed by the West Coast Expressway has the yellow collar soil(Hwang-To) primarily containing clay. Hwang-To serves as a soil appropriate for growing the watermelon and yam, but as a subgrade material not strong for constructing the roads. Particularly, the subgrade material of this study site was not qualified for the standard of the subgrade material quality. The properties of the subgrade layer showed that the strength of the subgrade material was not strong enough to sustain the subgrade strength in constructing the roads since the passing ratio of the No. 200 sieve was about 25％ to 82％ and the ground water level was early equal to subgrade one. Thus, the objective of this study was to present the methods obtaining the proper subgrade strength of cutting area to construct the secure and solid expressways in the fragile area.

原子力設備解体時に発生する極低レベル放射性コンクリート廃棄物は, 現時点で地下水位以上の地中に埋設処分する計画となっており, その際, 土砂等を充填することにより, 廃棄物間隙部へ空隙が残らないように措置することになっている. 筆者らは, これまでに埋設施工時条件を想定して, 締固め特性と締固め後の間隙分布に関する実大規模試験を実施し, 間隙部に覆土を混入し締固めることによって地表面の沈下や亀裂が防止できることを明らかにした. 本研究では, 埋設完了後に廃棄物周辺の地下水位が一時的に上昇・下降する状況を想定した試験を実施し, 廃棄物間隙部に覆土を混入し締固めることで覆土流入防止が可能なことがわかった. また, 廃棄物と覆土の境界に適切な粒度分布のフィルターを設置することによっても覆土流入防止が可能で, 地表面に変状を生じないことが確認された.

過去の調査によると, 高速道路の凍上被害は切土部と低盛土部に頻発しており, 通常の盛土部ではほとんど報告されていない. これは切土部と盛土部では地下水の給水条件が異なるためではないかと考え, 凍上量に及ぼす地下水位の影響を調べた. そのために, 室内大型凍上試験と実際の盛土施工地点での原位置凍上試験を実施している. 一連の試験結果から, 凍上量は地下水位の低下とともに急激に減少するものの, 土の初期含水比に強く依存することが見出された. これらの事実にもとづいて, 高速道路の盛土部の凍上率を推定する実用式を提案するとともに, その検証を行った.

This paper describes a method for analysis of various input parameters used in preparation of Landslide Hazard Zonation Maps. The method is based on the quantitative approach, which includes four Landslide Hazard Evaluation Factors grouped into four ranges of values. Since the various parameters are not equally important for estimation of Total Landslide Hazard Evaluation Factor (TLHEF), importance ratings are allocated to the different value ranges. Importance ratings for Lithological types (LT), Ground Water Level (GWL), Slope Angles (SA) and Soil Debris Cover (SDC) are defined using polynomial interpolation. With this procedure, each evaluation factor is related to the corresponding ratings using interpolation charts and equations. Based on the correlation between the adequate parameters and the rating, the Total Rating Hazard Evaluation Factor can be calculated.

A study has been carried out to investigate a slope in a granitic formation, that has been slowly but constantly moving since a small part near the toe of the natural slope was regraded in 1986 to make way for a road construction. Many scars on the slope surface suggest retrogressive failures have taken place. Investigation has been carried out to identify the causes and the extent of the failures so that an effective solution can be found. Site investigation with the geophysical procedures data shows the relatively shallow water table. Correlation between the pore pressure build up in the slope with the slope movements indicates that initiation of movement occurs quite consistently at a certain ground water level. The data gathered will be used to provide effective solutions to the slope movements and predict the quantum of the movements.

Probabilistic methods enable the rational treatment of uncertainties in the design and safety evaluation of rock structures, and consequently have become popular in mining engineering during recent years. In this study, advanced first-order second-moment (FOSM) method proposed by Hasofer and Lind (1974), that eliminates most of the limitations of the other probabilistic techniques, is taken as the reliability model in the analysis of plane failure. The advanced FOSM reliability approach treats the friction angle, cohesion and discontinuity orientation parameters as random variables considering the mean values, variances and correlation characteristics. The effects of ground water level and slope height on the design slope angle and the risk of slope failure are investigated together with the sensitivity of the reliability index to the level of uncertainty in the basic variables. Additionally, based on the criterion of minimizing expected total cost, the optimal slope angle to be used in design is...

Many wooden houses near a dune at Kariwa Village, Kashiwazaki City, Niigata Prefecture were damaged because of the liquefaction of the dune during the 2007 Niigata Chuetsu-offshore Earthquake, Mw = 6.8. This paper performs fully coupled dynamic finite element analysis to reproduce the ground liquefaction of two wooden houses. Here, wooden house A of which the ground was improved only using horizontal drainage pipes was fully damaged; however, wooden house B of which the ground was improved by horizontal drainage system to lower the ground water level, surface ground improvement, and steel-pipe piles was slightly deformed. For wooden house B, it was found, based on the numerical results, that steel-pipe piles were more effective liquefaction mitigation measure.

Triggering mechanisms and active landslide dynamics are to a large extent a function of rock and soil types involved. Among different types of active landslides in Slovenia, in the last few years, those in flysch have been of specific research interest. Different field and laboratory investigations have been carried out on several active landslides in flysch, mainly on the Slano Blato landslide in SW Slovenia. The research activities have been focused on the prevailing mechanisms of active landslides in flysch, specifically they have been directed into investigations on soil suction and its relationship with water content and shear-strength characteristics. These research activities have been carried out in the framework of the World Center of Excellence “Mechanisms of landslides in over-consolidated clays and flysch” of the Faculty of Civil and Geodetic Engineering of the University of Ljubljana, and the IPL-151 Project “Soil matrix suction in active landslides in flysch – the Slano Blato landslide case”. This paper presents the main results obtained.

Diaphragm walls frequently form structural retaining elements in civil engineering applications typically acting as permanent foundation walls in cut and cover structures or deep basements. The construction method is appropriate in gravel and sand formations with high water table levels where conventional excavation would be impracticable. Consequently, diaphragm walls are commonly primary barriers to groundwater infiltration but the completed walls may not entirely resist water penetration. Vertical panel joints are particularly susceptible to leaking, but unfortunately ingress through joints or wall panels does not become apparent until exposed by excavating. Moreover, if dewatering is used to reduce ground water levels during excavation, the full extent of infiltration through the walls may not become evident until dewatering is turned off and ground water levels recharge. This paper discusses use of resin injection to successfully control ground water ingress through vertical diaphragm walls joints. The walls formed lengthy approaches to a twin tube tunnel under a river on a high-speed rail link. Soils at the construction site were primarily gravels and clean sands with sustained ground water levels subject to tidal influences, at times ground water level almost equated to ground level. The majority of joints in the diaphragm walls were subject to various levels of water ingress, including running leaks. Adjacent to the tunnel portal, the exposed vertical diaphragm wall joints extended some 18 metres above invert slab level. Conditions leading to water ingress are explained with a discourse on resin selection, the client's involvement, proving of successful resin injection protocol and the practical implementation over a two year period. As with many remedial projects in civil engineering, the successful outcome was reliant on experienced engineers using empirical practices.

Bank erosion in populated areas could cause fatalities and property damage if banks collapse abruptly, compromising the integrity of residential buildings and civil facilities. Bank erosion study is in general a very complex problem because of it involves multi-processes such as bank surface erosion, bank toe erosion and bank material mechanic failure, etc. Each of these processes is related to several parameters: sediment size distribution, bank material cohesion, slope, homogeneity, consolidation, soil moisture and ground water level, as well as bank height. The bank erosion rate is also related to the strength of the flow in the river indicated by the flow shear stress, water depth and channel curvature, etc. In this study, the numerical model CCHE2D has been applied to study real-world bank erosion cases in a mountain river, Khoske Rud Farsan River, Iran, which is a braided river with high sediment loads and channel mobility; the bank erosion of this river is dominated by floods during rainy seasons.

これまで地すべりの移動特性を定量的に把握するための研究では地下水圧の時系列変化はほとんど考慮されていなかった。本論では簡単な地すべりモデルを用いて地下水位変動から長期的な地すべり移動量を求める一つの方法を提案した。