A new forecasting method for failure time of creep landslide based on nonlinear creep behavior and new pre-warning criterion

Abstract

The forecast of failure time of unstable slope and the definition of early warning threshold are very important for preventing landslide disaster and reducing its losses. Based on the monitoring curve of unstable slope deformation varying with time, the mathematical models are used to accurately describe the nonlinear creep behavior in the initial creep stage and the unstable creep stage of unstable slope and a forecasting method for creep landslide is proposed. In addition, this study examines an improved tangential angle criterion obtained by a new forecasting method. The results show that the initial creep stage of unstable slope can not be neglected for forecasting the failure time. The initial creep velocity v0 and the viscoelastic hysteresis coefficientξof the slope are determined at initial creep stage, which together control the creep process of the unstable slope. Moreover, in the secondary creep stage, there is an inverse relationship between the velocity and the critical tangential angle. According to the average velocity of the secondary creep stage, the early warning criterion of the landslide tangential angle is proposed. Combined with the forecast parameters of the unstable slope, comparative analysis of the critical tangential angle warning criterion and an improved tangential angle criterion, the early warning and forecasting system of landslide with creep characteristic is established. This system is applied to the early warning and forecasting analysis of reported soil and rock landslides cases with creep characteristics. The forecasting effect and applicability of the new method are studied in order to make it a better supplement to the early warning strategy of landslide.

Fourteen-Year Creep Monitoring and Benchmark Velocity Parameters of Natural Slopes at ‘Serra do Mar’, Brazil

“…Several studies summarize creep velocities and possible resulting failures. For example, Zhang et al (2022) present secondary stage velocities from 15 monitored soil and rock slopes around the world which eventually failed. Creep velocities ranged from 67 to as high as 4,500 µm/day (25mm/year to 1,6m/year), i.e., they all t in Class 2 -very slow movements in Fig.…”

“…Several papers focus on this issue, e.g., Saito (1969), Zavodni and Broadbent (1978), Varnes (1983), and Neto et al (2001). Intrieri et al (2019) presented a detailed review of creep failure methods and, more recently, Zhang et al (2022) described a new method for predicting failure time according to a critical tangential angle warning criterion. In general, prediction methods based on kinematic parameters may be classi ed into two main groups: a) empirical methods, which consider displacement velocities that critically increase before failure; and b) semi-empirical methods, which consider a general equation that relates the displacement rate to the acceleration, with some empirical constants.…”

An investigation into the physical factors that control slow mass movements

“…Mass movements are recognized as complex processes that encompass a broad range of rates, mechanisms, and resulting magnitudes of livelihood and infrastructural damage (e.g., Petley 2012). While Highland and Bobrowsky (2008)'s typology offers a clear delineation of mass movement type-based on rates and penetration depths-the development of a similar classification scheme for their causes is more challenging, as multiple factors and their feedback including (but not limited to) rainfall, lithology, rock strength and fracturing, and slope are difficult to deconvolve in a consistent way globally (e.g., Petley 2012;Zhang et al 2022). This is especially true for ultraslow (i.e., < 1 cm year −1 ) soil creep, initially proposed by Davis (1892).…”

“…These advances have unmasked soil creep as the culprit behind much spectacular infrastructural damage: for instance, creep was recently revealed to cause 38-44% of burst water mains in the UK, leading to total economic costs "more than double" those related to faster mass movements in that country (Pritchard et al 2014). Thirdly, increasing recognition of the number of catastrophic failures resulting from a sudden increase in downslope motion-a "slow-to-fast transition"-has motivated a need to enhance monitoring of creep rates in space and time in order to inform early-warning thresholds (e.g., Yao et al 2021;Zhang et al 2022).…”

Detection of former goaf and analysis of deformation characteristics of overburden in Dameidong coal mine

“…First of all, in the field of geological disaster prevention and control, many scholars have done a lot of research. Zhang et al (2022) proposed a prediction method of creep landslide by using mathematical model, which has important guiding significance for the prevention and control of landslide disaster. Through triaxial compression (RTC ) test, Zhang et al (2020) analyzed the deformation characteristics and mechanical response of unloading soil, and revealed the instability mechanism and response mechanism of loess slope under unloading.…”