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CONTENTS
Volume 32, Number 1, January10 2023
 


Abstract
To predict the consolidation behavior of dredged and reclaimed marine clays exhibiting consolidation settlement with large strains, the finite strain consolidation theory must be used. However, challenges in appropriately applying the theory and determining input parameters make design and analysis studies difficult. To address these challenges, design charts for predicting the consolidation settlement of reclaimed marine clays are developed by a numerical approach based on the finite strain consolidation theory. To prepare the design charts, a sensitivity analysis of parameters is performed, and influencing parameters, such as initial void ratio and initial height, as well as the non-linear constitutive void ratio-effective stress-permeability relation, are confirmed. Six representative Korean marine clays obtained from different locations with different liquid limits are used. The design charts for estimating the consolidation times corresponding to various degrees of consolidation are proposed for each of the six representative clays. The consolidation settlements predicted from the design charts are compared to those in previous studies and at an actual construction site and are found to agree well with them. The proposed design charts can therefore be used to solve problems related to the consolidation of reclaimed marine clays having large strains.

Key Words
consolidation settlement; design chart; finite strain consolidation theory; marine clay; non-linear constitutive relationship

Address
Sang-Hyun Jun: Infra Division, POSCO E&C, 241 Incheon Tower Daero, Incheon, 22009, Republic of Korea
Byung-Soo Park: Department of Smart City & Civil Engineering, Gangwon State University, Gangwon, 25425, Republic of Korea
Hyuk-Jae Kwon: Department of Civil Engineering, Cheongju University, Chungbuk, 28503, Republic of Korea
Jong-Ho Lee: Infra Division, POSCO E&C, 241 Incheon Tower Daero, Incheon, 22009, Republic of Korea;
Department of Civil Engineering, Kyungdong University, Gyeonggi, 11458, Republic of Korea


Abstract
In order to analyze the effect of the cyclic lateral loading on the response of a pile-soil system, a full-scale single steel pile was subjected to one-way cyclic loading. The test pile was driven into a bi-layered soil consisting of a normally consolidated saturated clay overlying a silty sandy layer, the site being submerged by water up to one meter above the mudline in order to reproduce the conditions of an offshore pile foundation. The aim of this paper is to present the main results of interpretation of the cyclic lateral tests in terms of pile deflections, bending moment, and cyclic P-Y curves. From these latter an absolute secant reaction modulus EAS,N was derived and a simple calculation model of the test single pile is proposed based on this modulus. Two applications of the proposed model are carried out, one with a 2D finite element modelling, and the second with a load transfer curves-based method.

Key Words
absolute secant modulus of lateral reaction; bi-layered soil; cyclic lateral loading; full-scale test; P-Y curves; single pile

Address
Hocine Haouari and Ali Bouafia: Laboratory NEIGE, Department of civil engineering, Faculty of Technology, University of Blida, Route de Soumâa, P.O.Box 270, R.P Blida, 09000, Blida, Algeria

Abstract
Deformability of road pavements in the form of ruts represent a safety risk for road users. In the procedures for dimensioning the pavement structure, the requirement that such deformations do not occur is imperatively included, which results in the appropriate selection of elements (material, geometry) of the pavement structure. Deformability and functionality, will depend of the correct design of pavement structure during exploitation period. Nevertheless, there are many examples where deformations are observed on the pavement structure, in the form of rutting at parts of the road with relatively short length, realised in the same climatic and the same geoenvironmental conditions. The performed analysis of deformability led to the conclusion that the level of deformation is a function of the speed of traffic. This effect is observed on city roads, but also outside of urban areas at roads with speed limits are significant, due to the traffic management, traffic jams (intersections, etc.). Still, the lower speed cause greater deformations. The authors tried to describe the deformability of flexible pavement structures, from the aspects of geotechnical problems, as a function of driving speed. Outcome of the analysis is a traffic load correction coefficient, in terms of using the existing methods of flexible pavement structures design.

Key Words
creep; flexible pavement structure; geotechnical problems; traffic load; traffic load correction coefficient

Address
Mato G. Uljarević, Snježana Z. Milovanović, Radovan B. Vukomanović and Dragana D. Zeljić: Faculty of Architecture, Civil Engineering and Geodesy, University of Banja Luka, Bulevar Vojvode Stepe Stepanovića 77/3,
Banja Luka, Bosnia and Herzegovina

Abstract
The three-dimensional failure criterion is essential for maintaining wellbore stability and sand production problem. The convenient factor for a stable wellbore is mud weight and borehole orientation, i.e., mud window design and selection of borehole trajectory. This study proposes a new three-dimensional failure criterion with linear relation of three in-situ principal stresses. The number of failure criteria executed to understand the phenomenon of rock failure under in-situ stresses is the Mohr-Coulomb criterion, Hoek-Brown criterion, Mogi-Coulomb criterion, and many more. A new failure criterion is the extended Mohr-Coulomb failure criterion with the influence of intermediate principal stress (o2). The influence of intermediate principal stress is considered as a weighting of (o2) on the mean effective stress. The triaxial compression test data for eleven rock types are taken from the literature for calibration of material constant and validation of failure prediction. The predictions on rock samples using new criteria are the best fit with the triaxial compression test data points. Here, Drucker-Prager and the Mogi-Coulomb criterion are also implemented to predict the failure for eleven different rock types. It has been observed that the Drucker-Prager criterion gave over prediction of rock failure. On the contrary, the Mogi-Coulomb criterion gave an equally good prediction of rock failure as our proposed new 3D failure criterion. Based on the yield surface of a new 3D linear criterion it gave the safest prediction for the failure of the rock. A new linear failure criterion is recommended for the unique solution as a linear relation of the principal stresses rather than the dual solution by the Mogi-Coulomb criterion.

Key Words
3D failure criterion; extended Mohr-Coulomb; geomechanics; in-situ stresses; triaxial principal stresses

Address
Mohatsim Mahetaji and Rakesh Kumar Vij: Department of Petroleum Engineering, School of Energy Technology, Pandit Deendayal Energy University- PDEU,
Gandhinagar, Gujarat, India
Jwngsar Brahma: School of Technology, Pandit Deendayal Energy University- PDEU, Gandhinagar, Gujarat, India

Abstract
This paper proposes a novel frame element on Winkler-Pasternak foundation for analysis of a non-ductile reinforced concrete (RC) member resting on foundation. These structural members represent flexural-shear critical members, which are commonly found in existing buildings designed and constructed with the old seismic design standards (inadequately detailed transverse reinforcement). As a result, these structures always experience shear failure or flexure-shear failure under seismic loading. To predict the characteristics of these non-ductile structures, efficient numerical models are required. Therefore, the novel frame element on Winkler-Pasternak foundation with inclusion of the shear-flexure interaction effect is developed in this study. The proposed model is derived within the framework of a displacement-based formulation and fiber section model under Timoshenko beam theory. Uniaxial nonlinear material constitutive models are employed to represent the characteristics of non-ductile RC frame and the underlying foundation. The shear-flexure interaction effect is expressed within the shear constitutive model based on the UCSD shear-strength model as demonstrated in this paper. From several features of the presented model, the proposed model is simple but able to capture several salient characteristics of the non-ductile RC frame resting on foundation, such as failure behavior, soil-structure interaction, and shear-flexure interaction. This confirms through two numerical simulations.

Key Words
flexure-shear critical members; shear-flexure interaction; soil-structure interaction; Timoshenko frame element; Winkler-Pasternak foundation

Address
Suchart Limkatanyu: Department of Civil and Environmental Engineering, Faculty of Engineering, Prince of Songkla University, Songkhla 90110, Thailand
Worathep Sae-Long, Nattapong Damrongwiriyanupap and Thanakorn Chompoorat: Civil Engineering Program, School of Engineering, University of Phayao, Phayao 56000, Thailand
Piti Sukontasukkul: Construction and Building Materials Research Center, Department of Civil Engineering, King Mongkut

Abstract
Microbially induced carbonate precipitation (MICP) is extensively discussed as a promising topic for ground stabilization. The practical effect of stabilizing the expansive soil is presented in this paper with a logical process from the bacterial activity to the treatment technology. Temperature, pH, shaking frequency, and inoculation amount are discussed to evaluate the bacterial activity. The physic-mechanic properties are also evaluated to discuss the effect of the MICP process on expansive soil. Results indicate that the MICP method achieves the mitigation of expansion. The treated soil has a low proportion of fine particles (< 5 um), the plasticity index significantly decreases, and strength values improve much. MICP process has a significant cementation effect on the soil matrix. Moreover, the infiltration model test presents the coating effect on the topsoil. According to the relation between the CaCO3 content and the treatment effect, the topsoil has better treatment than the deeper soil.

Key Words
cementation effect; coating effect expansion; expansive soil; Microbially induced carbonate precipitation (MICP); the treated soil

Address
Zheng Lu: State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics,
Chinese Academy of Sciences, Wuhan 430071, China;
2Hubei Key Laboratory of Geo-Environmental Engineering, Wuhan 430071, China
Yu Qiu: State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics,
Chinese Academy of Sciences, Wuhan 430071, China;
University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
Jie Liu: Transportation Planning Survey and Design Institute Co., Ltd., Urumqi 830006, China
Chengcheng Yu: CCCC Second Harbor Engineering Co., Ltd., Wuhan, Hubei 430040, China
Hailin Yao: State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics,
Chinese Academy of Sciences, Wuhan 430071, China


Abstract
The coefficient of lateral earth pressure at rest in loose sand during virgin loading, Ko, and during unloading, Ko, have been determined from laterally confined load-unload tests. The tests included measurement of lateral pressure with null pressure gauges, side wall friction with newly designed friction meters and applied pressure and base pressure with load cells. The importance of accounting for side-wall friction when evaluating the distribution of vertical pressure over the height of the soil specimen was demonstrated. Relatively uniform friction was observed during loading, but this was not the case during unloading unless friction reduction measures were employed. While the measured value of Ko was found to be close to, if slightly higher than the value commonly estimated on the basis of friction angle, o, the ratio of Ko, to Ko was found to reasonably fit an expression of the form Ko Ko⁄=1+C∙log (OCR), with C equal to 1 in the present tests.

Key Words
𝐾0; confined loading; confined unloading; loose sand; side-wall friction

Address
Shay Nachum, Mark Talesnick and Sam Frydman: Faculty of Civil & Environmental Engineering, Technion – Israel Institute of Technology, Haifa, 32000, Israel

Abstract
The slope of an open cut tunnel is located above the exit of the Leijia tunnel on the Changgan high-speed railway. During the excavation of the open cut tunnel foundation pit, the slope slipped twice, a large landslide of 92500 m formed. The landslide body and unstable slope body not only caused the foundation pit of the open cut tunnel to be buried and the anchor piles to be damaged but also directly threatened the operational safety of the later high-speed railway. Therefore, to study the stability change in the slope of the open cut tunnel under heavy rain and excavation conditions, a 3D numerical calculation model of the slope is carried out by Midas GTS software, the deformation mechanism is analyzed, anti-sliding measures are proposed, and the effectiveness of the anti-sliding measures is analyzed according to the field monitoring results. The results show that when rainfall occurs, rainwater collects in the open cut tunnel area, resulting in a transient saturation zone on the slope on the right side of the open cut tunnel, which reduces the shear strength of the slope soil; the excavation at the slope toe reduces the anti-sliding capacity of the slope toe. Under the combined action of excavation and rainfall, when the soil above the top of the anchor pile is excavated, two potential sliding surfaces are bounded by the top of the excavation area, and the shear outlet is located at the top of the anchor pile. After the excavation of the open cut tunnel, the potential sliding surface is mainly concentrated at the lower part of the downhill area, and the shear outlet moves down to the bottom of the open cut tunnel. Based on the deformation characteristics and the failure mechanism of the landslides, comprehensive control measures, including interim emergency mitigation measures and long-term mitigation measures, are proposed. The field monitoring results further verify the accuracy of the anti-sliding mechanism analysis and the effectiveness of anti-sliding measures.

Key Words
field monitoring; finite element method; open cut tunnel; rainfall; slope deformation; stabilization treatment

Address
Guoping Hu, Yingzhi Xia, Xiaoxue Ruan and Hui Li: Road Bridge and River-crossing Engineering, School of Civil and Transportation Engineering,
Henan University of Urban Construction, Pingdingshan, Henan 467036, China
Lianggen Zhong: Changjiu Intercity Railway Co., Ltd, Nanchang, Jiangxi 330002, China


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