Jie Zhang

Tongji University · Department of Geotechnical Engineering

Outlier detection is an important task in data-driven geotechnics. It is noted that many existing methods for outlier detection (e.g., Bayesian learning, neural networks) may pose computational challenge for conventional geotechnical practitioners. Towards this aspect, this study proposes a simple, fast, and explainable method for detecting outlier...

Landslide susceptibility maps can provide important information for managing regional landslide risks. Traditionally, data-driven and physically-based models are widely used for rainfall-induced landslide susceptibility mapping, but each method has limitations. In this study, a hybrid method that integrates a data-driven model and a physically-base...

Geotechnical site characterization using multivariate, limited (sparse), and missing (incomplete) data is an important but challenging task, particularly in high dimensions. Towards this problem, this study proposes a Bayesian vine algorithm. In the proposed algorithm, the task of Bayesian update in higher dimensions is translated into a series of...

Quantifying the uncertainty of the bearing capacity of piles is crucial in the context of reliability-based design (RBD) for pile foundations. The utilization of site-specific load test data plays a pivotal role in reducing the uncertainty associated with bearing capacity, thereby enhancing the overall design of pile foundations. However, prior to...

Constructing a \hl{joint distribution} model for rainfall characteristics is an important task for risk-based hydrologic design. However, most stochastic rainfall models are limited to \hl{bivariate frequentist distribution} and cannot be easily generalized to multivariate ($\geq3$) Bayesian settings. Towards this problem, this study presents a Bay...

This study aims to develop a new technique for deriving the reliability index in original physical space using C-vine copula models integrated with the environmental contour method. In the proposed approach, the minimum of the reliability index is considered an objective function, whereas the coordinates on the environmental contour satisfying the...

Evaluating the exceedance probability within a time period (EPT) of the runout distance of rainfall-induced landslides is important for the quantitative risk assessment (QRA) of rainfall-induced landslides. However, assessing the EPT of the runout distance of rainfall-induced landslides using a mechanics-based method remains a challenging problem s...

The API p-y method is widely used in the design of offshore wind turbines (OWTs) monopiles at present. This study systematically evaluates the model uncertainty of the p-y method for OWT monopiles and proposes a two-stage calibration approach for evaluating the model bias factor. To overcome the difficulty of limited field tests, a high-fidelity ba...

Uncertainties are pervasive in geotechnical engineering. Reliability analysis provides a scientific way to characterize, model, and assess the impact of uncertainties in geotechnical engineering. Due to the increase in processing power of personal computers, the field of geotechnical reliability has experienced significant advancements since 1990s....

Due to the existence of uncertainties in geotechnical engineering, the performance of a geotechnical system can hardly be predicted deterministically. In such a case, the performance of a geotechnical system can be measured by the probability of failure, i.e., the probability that the designed performance cannot be achieved.

Uncertainties are pervasive in geotechnical engineering, such as the inherent variability of the soil, the measurement error due to imperfect testing, the statistical uncertainties due to limited amount of testings, and uncertainties due to modeling assumptions.

Although first-order reliability methods introduced in the previous chapter are efficient and easy to apply, they may not work well for problems with high dimensionality, nonlinear performance functions, and multiple failure modes (e.g., Schuëller et al. (Schuëller et al. in Probab Eng Mech 19:463–474, 2004); Song et al. (Song et al. in ASCE-ASME J...

The RSMs are a set of techniques used in the empirical study of relationships [1]. It was proposed by Box and Wilson in 1951 [2], and it is currently widely used in reliability analysis.

The uncertainty in geotechnical engineering depends on the amount of information available. When more information is available, such information can be used to reduce the uncertainty in geotechnical engineering, and hence improve decision making.

The working stress design has long been used in civil engineering (e.g., Barker et al. in Manuals for the design of bridge foundations: shallow foundations, driven piles, retaining walls and abutments, drilled shafts, estimating tolerable movements, and load factor design specifications and commentary. Transportation Research Board, Washington, DC,...

Due to the complex geologic, environmental, and physical–chemical processes, geotechnical properties vary spatially even in the same geological unit, referred to as spatial variability.

Landslides significantly threaten human life and infrastructure, requiring accurate and timely identification for effective hazard assessment and management. In this study, we propose a novel approach for landslide identification by integrating Geographic Object-Based Image Analysis (GEOBIA) with advanced techniques and machine learning algorithms....

Large-diameter monopile is the most widely used foundation for offshore wind energy converters, which behaves as a semi-rigid/rigid pile under lateral loading. However, the current laterally loaded monopile design method recommended by API ignores the toe-kick phenomenon and the base shear force (Q b), which was developed initially for slender pile...

The monopile-supported offshore wind turbines (OWTs) are increasingly installed in more challenging seabed environments, resulting the reliability of the monopile foundation attract more attentions. The reliability of the monopile foundation is largely uncertain due to uncertainties in correlated wind and waves and spatially varying soils. To addre...

Assessing the annual probability of slope failure under rainfall (PFA) is a key step in quantitative risk assessment (QRA) of rainfall-induced landslides. To assess the PFA using mechanics-based methods, the uncertainty of rainfall in a year needs to be considered. Intensity–duration–frequency (IDF) curves are a widely available rainfall model. It...

Complex marine environment causes significant variations in the dynamic loads and soil parameters that affect the design of a monopile. Despite these uncertainties, a multi-objective optimization technique is developed to produce the optimal designs. This optimization is based on the robust design concept, in which the design robustness, cost, and...

Due to uncertainties in metocean conditions and soil properties at the offshore wind farm, the performance of the monopile foundation of offshore wind turbines (OWTs) is also uncertain. In this study, a performance-based assessment method is suggested to calculate the annual probability of exceedance of a performance measure of monopile foundations...

The inverse velocity (INV) method is widely used for predicting the slope failure time. When applying the INV method, the inverse velocity can be assumed to be a linear and non-linear function of time, respectively, which are called linear and non-linear INV methods in this paper, respectively. Very few guidance is available in the literatures on t...

This paper is motivated by the Time Capsule Project (TCP) of the International Society for Soil Mechanics and Geotechnical Engineering (ISSMGE). The historical developments of geotechnical risk and reliability are reviewed for the past six decades. The key features distinguishing geotechnical and structural engineering are the natural origin of the...

The liquefaction potential index (LPI) has been widely used to develop fragility function for predicting the liquefaction-induced ground failure. As the fragility function tends to vary from one region to another, it is best developed based on region-specific data. When the amount of region-specific data is limited, how to develop the region-specif...

Traditionally, the factor of safety (FOS) is widely used to account for uncertainties in the design of slopes within the framework of working stress design. As the uncertainties involved in the design of slopes vary, the same FOS may correspond to the different levels of reliability. In this study, the advanced first order reliability method is use...

In the design of shield tunnels, it is expected that a design can be more economical as more site investigation data are available. Nevertheless, the cost of site investigation will also increase as more site investigation data are required. It is thus important to assess the potential benefit of a site investigation program before it is conducted...

Assessing the probability of rainfall-induced slope failure during a given exposure time is essential for the quantitative risk assessment of landslide hazards. In current mechanics-based methods, the focus is often on the annual failure probability, and the failure events of a slope under different rainfalls are assumed to be fully correlated. In...

For a tunnel driven by a shield machine, the posture of the driving machine is essential to the construction quality and environmental impact. However, the machine posture is controlled by the experienced driver of shield machine by setting hundreds of tunneling parameters empirically. Machine learning (ML) algorithm is an alternative method that c...

Stabilizing piles have been widely used as an effective measure to reinforce slopes. In this paper, a hierarchical response surface method is presented to evaluate the reliability of a pile-slope system efficiently. The suggested method can be used to identify the minimum reliability indexes of different types of failure modes. It can also be used...

In the Chinese code models for seismic design, the shear wave velocity (Vs)-based model for liquefaction potential assessment is built based on the depth consistency assumption, i.e., the seismic demand is a non-decreasing function of the soil depth. It provides an alternative way to construct empirical models based on past case histories. However,...

The site investigation (SI) is important to reduce the uncertainty of the slope soil properties. Its effectiveness is highly related to the planning of an SI program such as borehole layout. It is thus tempting to assess the potential uncertainty reduction of an SI program. This paper presents a method to assess the expected benefit (EB) of an SI p...

Most previous studies on the quantitative risk assessment (QRA) of landslides focused on the probability of slope failure at the pre-failure stage and adopted empirical models for consequence analysis. The conventional approaches simplify the relationship between the pre-failure state and the post-failure behavior and cannot reasonably account for...

The floor plan recognition problem is a sophistical and time-consuming task that requires architects to craft with their professional skills and tools. To solve Raster to vector (R2V) issues, this paper presents a deep-learning-based framework mainly consisting of YOLOv5, deep residual network (DRN), and OCR extraction algorithms. Our work can be i...

The influence of spatial variability of soil on geotechnical engineering such as the ultimate bearing capacity of shallow foundation can be considered by reliability analysis based on random field theory. However, reliability analysis can only estimate the reliability index or failure probability of geo-structures, which cannot identify the importa...

In this paper, a performance-based method is suggested to assess the permanent displacement of a slope using two-dimensional dynamic analysis considering both uncertainties in ground motions and basic soil parameters. In the suggested method, the statistics of the permanent displacement is first analyzed at different peak ground acceleration levels...

Rectangular reinforced concrete (RC) culverts are widely used in drainage systems of many megacities, which may experience significant deterioration due to the corrosive sewage environment. How to assess the performance of existing RC culverts is crucial to the public safety. Currently, very few studies have been reported on the assessment of the p...

The data-driven phenomenological models based on deformation measurements have been widely used to predict the slope failure time. The existence of the observational uncertainty and the model uncertainty could make the predicted failure time from the phenomenological models different from the actual time of slope failure. Currently, very limited st...

The soil-water characteristic curve (SWCC) is a significant prerequisite for studying the mechanical properties of unsaturated soil. As experimental measurement of the SWCC is time-consuming, empirical methods have been suggested to estimate the SWCC. However, the uncertainty associated with SWCC can be substantial. In this paper, a hybrid method b...

The annual failure probability of a slope is an important input for the risk assessment of rainfall-induced landslides. Currently, the annual probability of slope failure under rainfall conditions is usually estimated through statistical analyses of historical landslide events in a region, which cannot consider the local conditions such as soil pro...

The study of rock fragmentation mechanism significantly contributes to the advancing speed of tunnel boring machines (TBMs). In this sense, numerous factors are shaping the rock fragmentation mechanism of their disc-cutters. Among them, rock structural parameters, such as joint inclination, orientation, spacing, etc., considerably impact cutting fo...

The blow count (N) measured from the standard penetration test is widely used to predict the shear wave velocity (Vs) of soils. As the N - Vs relationships vary from one region to another, the N - Vs relationship in a region is often determined based on the regional data. When there is no region-specific data or when the region-specific data is lim...

In China, the required blow count is used to represent the effect of seismic loading, which can provide engineers an intuitive feeling about how much effort is needed to improve the soil if its liquefaction resistance is not adequate. A fundamental assumption in the Chinese seismic design code methods is depth consistency, i.e., the required blow c...

Site investigation is widely used for uncertainty reduction and design improvement in slope engineering. Before the site investigation is implemented, it is important to assess and compare the effectiveness of different site investigation programs. In this paper, an efficient method for analyzing the effectiveness of a site investigation program fo...

Landslides along highways not only induce direct losses related to cost of replacement, repair or maintenance due to physical damage, but also induce indirect losses due to reduction in production in different sectors in an economic system. In this study, a method is suggested to assess the indirect losses of landslides along highways, where the im...

To enhance the computational efficiency in slope reliability analyses, a binary classification method (BCM) that takes advantage of a judgement-based strength reduction method (SRM) and an active-learning support vector machine (SVM) was developed to conduct system reliability analyses of layered soil slopes. The SVM was naturally employed to estab...

Realistic estimation of the uncertainty associated with the bearing capacity, which is often represented by the uncertainty of a model bias factor, is important to reliability-based design of pile foundations. Due to the existence of cross-site variability, the statistics of a model bias factor may vary from one site to another. Also, as the number...

During the 2003 Bachu earthquake in China, the liquefaction phenomenon was widely observed. However, the standard penetration test–based method suggested in the national seismic design code in China significantly underestimates the liquefaction potential in Bachu. In this paper, a model bias factor is used to represent the effect of model uncertain...

As a slope may have numerous potential slip surfaces, its failure probability as a system is usually different from that of a single slip surface. Nevertheless, the system failure probability of a slope is often governed by several representative slip surfaces. How to identify the representative slip surfaces is important for system reliability ana...

Youd’s method is a widely adopted standard penetration test based approach for evaluation of liquefaction potential. This method was established by pooling the post-earthquake survey data collected from different regions of the world, and its accuracy may vary when applied in different regions. This paper investigates the inter-region variability a...

Landslides threaten the safety of vehicles on highways. When analyzing the risk of a landslide hitting moving vehicles, the spacing between vehicles and the types of vehicles on the highway can be highly uncertain and have often been omitted in previous studies. Using a highway slope in Hong Kong as a case study, this paper presents a method for as...

Probabilistic methods are increasingly used to quantify the effect of uncertainties on slope stability assessment. The shear strength reduction method can be used for slope stability analysis without prior assumption on the shape of the failure surfaces, and hence is an attractive method for slope stability analysis. Since it is computationally mor...

Soil spatial variability is difficult to evaluate due to insufficient test data. An alternative option is estimation by indirect methods such as inverse analysis. In this paper, two examples are presented to demonstrate the capability and accuracy of the probabilistic estimation method to characterize soil spatial variability with displacement resp...

A deep excavation has a significant influence on existing tunnels. However, there is currently a lack of simple and practical assessment methods for predicting this influence. In this paper, a simplified model is proposed to predict the displacement of existing tunnels caused by a laterally-adjacent deep excavation in the soft soil layers. Using nu...

The inverse velocity method is widely used for slope failure time prediction. In practice, the presence of factors like measurement error, environmental noise, and modeling assumptions may make the predicted failure time different from the actual failure time. While the traditional inverse velocity method can provide useful information about the pr...

Abstract. Landslides threaten the safety of vehicles on highways. Nevertheless, a rigorous quantitative highway landslide risk assessment seems difficult. Using a case study in Hong Kong, this paper presents a method for quantitative risk assessment for highway landslides. The suggested method consists of three parts, i.e., analysis of annual failu...

Natural heterogeneity of soil hydraulic properties is significant for the design and construction of geotechnical structures, and should be adequately characterized. Accurate measurements of hydraulic properties remain a difficult job and do not always work well for further design and analysis. Field hydraulic monitoring data reflects the overall s...

As numerical models are increasingly used as a design tool in geotechnical engineering, it is highly desirable if geotechnical reliability analysis can be conducted based on numeral models. Currently, the practical use of geotechnical reliability analysis‐based numerical models is still quite limited. In this study, an easy to access method is deri...

Accidental surcharges caused by unauthorized damped waste are the most serious hazard threatening the serviceability and structural safety of shield tunnels in Shanghai, China. It is highly desirable to assess the effect of such accidental surcharges on the performance of shield tunnels. Nevertheless, the occurrence and magnitude of the accidental...

Field measured data reflect real response of soil slopes under rainfall infiltration and can provide representative estimates of in situ soil properties. In this study, an efficient probabilistic back analysis method for characterization of spatial variability of soil properties is used to investigate the effects of field responses with various mon...