Search

As immovable stone cultural heritage is kept in the open air, they are more susceptible to damage, and damage detection is very important for the protection and restoration of cultural heritage. This is especially true for gold-overlaid stone cultural heritage, which is usually more complicated than ordinary stone carvings. However, the detection of cultural heritage damages is mainly based on expert visual inspection, which is often subjective, time-consuming, and laborious. This paper uses the Mask R-CNN algorithm to rapidly and accurately detect the gold foil shedding of stone cultural heritage through two-dimensional images. The research data are from the high-precision images of the Dazu Thousand-Hand Bodhisattva Statue (World Heritage, UNESCO) in Chongqing, China. After cleaning and augmentation, 1900 images are input into Mask R-CNN model for training. Finally, the average precision value (AP) for detecting gold foil shedding is found to be 0.967. In order to test the performance of the model, the new images that do not participate in the training period are used, and it is found that the model can still accurately detect the gold foil shedding even if there are interference factors. This is the first attempt to detect the damages of gold-overlaid stone cultural heritage based on a deep learning algorithm, and it has achieved good results. [ABSTRACT FROM AUTHOR]

The literature on urban vitality tends to focus on the built environment. This paper argues that some important processes in shaping vitality may be overlooked without examining the intensity and diversity of economic and human activities. Using newly developed spatial big data and adopting the methods of multi-indicator measurement and spatial analysis methods, we analyzed the pattern of urban vitality in Chongqing, a provincial city in western China and, on this basis, evaluated the creation and maintenance of urban vitality from the economic and human activities perspective. Our findings indicate that the impacts of economic and human activities are positive and significant. Among the three intensity and diversity indicators, economic intensity and population density show an effect on urban vitality stronger than that of economic diversity. However, economic diversity has the strongest superposition or interactive effect, and is thus an important foundation dynamic. The positive effect of population density on urban vitality is largely a result of Chongqing's jobs-housing balance. The case of Chongqing highlights the importance of topographic features, historical inheritance, large-scale migration, and cultural activities in shaping the distinctive vitality pattern of a city. This study contends that the creation and maintenance of urban vitality can not be fully explained without incorporating the impacts of economic and human activities. It contributes to a comprehensive measurement of urban vitality and enriches its connotations. [ABSTRACT FROM AUTHOR]

In the midsummer of 2022, a rare regional high-temperature event occurred in the Yangtze River Basin. Chongqing, as the center of this event, also experienced its strongest high temperature since 1961. In this paper, the characteristics of this event in Chongqing are reviewed in detail and compared with those of 2006. We have confirmed the following conclusions with detailed data: (1) In the midsummer of 2022, the number of days that the daily maximum temperature is exceeding 35 ℃ in Chongqing was the most since 1961, with the number of days that the daily maximum temperature above 40 ℃ increasing significantly compared with 2006. (2) The impact range of this event in Chongqing was quite extensive, especially the range with the daily maximum temperature exceeding 40 ℃ was the widest since 1961. (3) The high-temperature event was more extreme in 2022 than that in 2006. The maximum of daily maximum temperature was 45 ℃, and this is the first time that China has recorded a high temperature of 45 ℃ outside Turpan. There were 5 stations with daily maximum temperature exceeding 44 ℃, accounting for 1/3 of the number of stations with such temperature (15 stations) in China. (4) In the midsummer of 2022, Chongqing was dominated by the compound high-temperature day. Compared with 2006, the daytime high-temperature day decreased significantly, while the compound one increased obviously. [ABSTRACT FROM AUTHOR]

The operation status of the underground public space pedestrian system is of varying quality, but decision-makers and operators have no way of knowing its current operation status and how to retrofit it. In this paper, the social network model is adopted to compare and analyze the characteristic parameters of urban underground public space networks and users' pedestrian routes in 13 cases in the main urban area of Chongqing to judge the suitability of the two networks. The results show a mismatch between the existing urban underground public spaces and users' walking paths, with most users choosing to move within a fixed range and preferring to stop at nodes with larger areas, while there is an obvious waste of resources in the rest of the nodes. The overall connectivity and aggregation are generally low although the number of nodes in transit between the two networks matches. In addition, with different types of space compared, the cross-block urban underground public space network is more suitable for users' pedestrian routes, followed by the square and street types, and the compound type is ranked last. [ABSTRACT FROM AUTHOR]

The planning process in urban rail transportation can be split into several stages, including line planning, timetabling, rolling stock scheduling and so on. The outcome of a stage provides inputs or constraints to the subsequent ones. However, while the output can be good or optimal at each stage, it rarely considers the global quality for the overall planning process. Furthermore, problems tackled at planning phase often use a more aggregate representation of reality, to achieve a more general overview. An integrated approach, while more complex to solve, may mitigate the gap between solution of different stages and a validation of a plan would still be required before its implementation in practice. In this paper, we focus on integrated optimization of train timetabling and rolling stock circulation for urban rail transit line with time-based origin-destination-dependent passenger travel demand and heterogeneous rolling stocks. The aim is to generate a comfortable timetable for passengers and an efficient timetable for operators. The objective is to minimize the total waiting time for passengers and the costs for operators, while constraints regarding train movements, passenger boarding and alighting, available rolling stocks and their capacity are considered. A mixed integer linear programming model is formulated and solved by an iterative programming approach. Computational experiments are performed on the Chongqing Rail Transit Line 2 to verify the efficiency and effectiveness of the proposed model and solving method. With respect to CPLEX, results show the proposed iterative programming approach has advantages both on computation time and solution quality. [ABSTRACT FROM AUTHOR]

Using the CRITIC method, comprehensive index evaluation method, VAR model, coupling coordination model and other methods, this paper evaluates the comprehensive development of the population economy and eco-geological environment composite system in the twin-city economic circle of Chengdu–Chongqing region from 2000 to 2020, verifies the dynamic coupling relationship between subsystems and measures the coupling coordination degree of complex system. Meanwhile, the differences in the development process of each subsystem are discussed and the spatial–temporal evolution characteristics and laws of coupling coordination of the composite system during the research period are analyzed. The results reveal the following: (1) There is a long-term coordinated relationship between population, economy and eco-geological environment in Chengdu–Chongqing region, which have the conditions for emergence and generation. (2) The subsystems of population, economy and eco-geological environment in Chengdu–Chongqing region show an overall upward trend, among which the Sichuan part obviously outperforms the Chongqing part. Besides, the growth rate of the economy subsystem is significantly higher than that of the population, eco-geological environment subsystem. (3) The coupling coordinated development of the composite system has shown a benign upward development trend, gradually changing from "composite spiral structure" to "two cores outstanding, peripheral collapse, the west superior to the east", while the main coordination state has developed from "Basic synergy—Economic lag" in 2000 to "Basic synergy—Population lag" in 2022. In addition, Cheng-De-Mian and Yuzhong districts with the better level of economic development have shown "Advanced synergy—Ecological lag". [ABSTRACT FROM AUTHOR]

Spatial prediction(SP) based on machine learning(ML) has been applied to soil water quality, air quality, marine environment, etc. However, there are still deficiencies in dealing with the problem of small samples. Normally, ML requires large amounts of training samples to prevent underfitting. And the data augmentation(DA) methods of mixup and synthetic minority over-sampling technique(SMOTE) ignore the similarity of geographic information. Therefore, this paper proposes a modified upsampling method and combines it with the random forest spatial interpolation(RFSI) to deal with the small sample problem in geographical space. The modified upsampling is mainly reflected in the following two aspects. Firstly, in the process of selecting the nearest points, it is to select points with similar geographic information in some aspects of the category after classification. Secondly, the selected difference is the difference of each category. In order to verify the effectiveness of the proposed method, we use daily precipitation data for January 2018 in Chongqing. The experimental results show that the combination of the modified upsampling method and RFSI effectively improves the accuracy of SP. [ABSTRACT FROM AUTHOR]

On October 2017, due to continuous rainfall, there was a massive river blockage induced by a landslide in Guang'an Village, Chongqing, China. Long-term monitoring analysis has shown that there remain four strong deformation areas on the slope, which seriously threaten the life and property of nearby residents. In this paper, a granular flow model and an elasto-visco-plasticity model were applied to reproduce and predict the landslide event that hit Guang'an Village. The results showed that the landslide gradually moved along the sliding surface, pushing loose deposits and blocking the Xixi River. The numerical reproduction results of the 2017 event are consistent with the actual slope deformation and failure process and deposit morphology. The simulated maximum depth-averaged velocity of this landslide was approximately 1.89 m/s, and the height of the landslide dam was approximately 10 m. After the landslide occurred in 2017, several large deformation areas appeared in the vicinity of the sliding area, and the right rear side of the sliding mass in area III has the largest deformation volume, accompanied by the most developed surface crack and the most intense deformation. There is a risk that the Xixi river will be blocked again. Therefore, with the same parameter and numerical model, a sliding–pushing–blocking dynamic prediction analysis of the strong deformation area III was conducted. The pushing motion of the mass in this area will reactivate the landslide mass observed in 2017. The maximum depth-averaged velocity of deformation area III was 0.5 m/s, and the maximum depth-averaged velocity of landslide deposition was 0.45 m/s. The length of the blocking dam formed by the mass of deformation area III along river was approximately 780 m, 30 m longer than that in 2017. The predicted height of the landslide dam was 14.5 m, approximately 4.5 m higher than that in 2017. The length of the landslide dam reservoir was predicted to be 2.55 km along the Xixi River, which may submerge the Waping Village. This study supports the landslide hazard prevention, reveals the whole movement process of sliding-pushing-blocking, and provides a new research idea and method for the landslide movement prediction. Hence, this study can serve as a reference for the hazard prevention and mitigation of such chain disasters. [ABSTRACT FROM AUTHOR]

Owing to the lockdowns associated with the Coronavirus Disease 2019(COVID-19) pandemic, carbon emissions were significantly reduced. However, the accurate impacts on the personal transport sector since then remain unclear. To further investigate the influence of sudden public health emergencies on actual carbon emissions from personal electric vehicles, this paper examined the travel patterns and corresponding carbon emissions of plug-in hybrid electric vehicles (PHEVs) operating in Chongqing, China, before and after COVID-19. The results revealed that the pandemic has reshaped the travel patterns of vehicle drivers, with a 9 % reduction in the postpandemic fleet average daily travel mileage. Currently, the total daily carbon emissions of a PHEV with a range of 80 km (PHEV80) are 6.24 kg, which is 13 % lower than emissions from conventional vehicles and 32 % higher than those from electric battery-powered vehicles before the pandemic. Since COVID-19, there has been a 24 % decrease in carbon emissions from PHEV80 vehicles for the fleet and a 30 % maximum increase for individuals. Furthermore, considering the integration of 50 % renewable energy into China's power grid by 2025, PHEVs can better mitigate the fluctuations in carbon emissions associated with sudden public health emergencies compared with conventional vehicles. [ABSTRACT FROM AUTHOR]

Based on the upper limit theorem of limit analysis and the Hoek-Brown failure criterion and considering the adverse influence of the seepage force, we established a stability analysis method of analyzing the water-resistant rock mass of a karst tunnel face, developed a critical safety thickness criterion for water inrush caused by the instability of the tunnel face, and conducted a sensitivity analysis of the main influencing parameters. We defined the safety coefficient (k) of the tunnel face's resistance to water-inrush instability during the tunnel excavation process and analyzed the dynamic evolution characteristics of the tunnel face's stability during the tunnel construction according to the safety coefficient. We used the method introduced in this paper to calculate the safe thickness of the water-resistant rock mass of the Xiema tunnel face in the first horizontal line of the Chongqing Expressway where it is adjacent to karst cavity 268. We compared these results with the calculation results of a method that did not consider the adverse influence of the karst water seepage force. The results showed that the safety thickness of the water-resistant rock mass calculated using the method proposed in this paper more accurately conformed to the actual situation of the project, which can more effectively ensure the construction safety of the tunnel segment adjacent to the anterior, concealed, high-pressure, water-rich karst cavity. The results of this study hold great significance for improving the predictability and targeted prevention of water-inrush disasters in karst tunnels. [ABSTRACT FROM AUTHOR]

As an effective reinforcement learning (RL) algorithm, Q-learning has been applied to energy management strategy of hybrid electric vehicle (HEV) in recent years. In the existing literatures, the values of three hyperparameters based on Q-learning are all given in advance, which are respectively exploratory rate ε, discount factor γ and learning rate α. However, different values of hyperparameters will influence on fuel economy of the vehicle and offline computation speed. In this paper, it is proposed that the method of optimization on hyperparameters adapting to driving cycle. Firstly, the mathematical model between three hyperparameters and iteration times is established based on inherent regularity of hyperparameters influencing on vehicle performance respectively. Secondly, it is determined that the optimal changing index k_index of iteration number based on Q-learning corresponding to typical driving cycles. Finally, the simulation model of Yubei District in Chongqing is constructed based on the method of Kullback-Leibler (KL) driving cycle identification. The simulation results indicate that equivalent fuel consumption of the proposed strategy is reduced by 0.4 % and the offline operation time is reduced by 6 s. It can be concluded that the proposed strategy can not only improve fuel economy of the vehicle, but also accelerate the computation speed. [ABSTRACT FROM AUTHOR]

The high environmental pollution load caused by the massive pollutant emissions and the accumulation of endogenous and cross-regional pollution has become an important obstacle to the current ecological civilization construction in the Yangtze River Economic Belt (YREB) in China. Taking the YREB as an example, by using four environmental pollutant emission indicators, including chemical oxygen demand (COD), ammonia nitrogen (NH3-N), sulfur dioxide (SO2), and nitrogen oxides (NOx), this paper established an environmental pollution load index (EPLI) based on the entropy-based measurement. Moreover, the Spatial Durbin Model was used to quantitatively analyze the drivers and spatial effects of environmental pollution load. Finally, specific scientific references were provided for formulating environmental regulations of pollution source control in the YREB. The results showed that: 1) During 2011–2015, the EPLI in the YREB was reduced significantly and the environmental pollution load increased from upstream to downstream. Among them, the pollution load levels in the Upper Mainstream subbasin, Taihu Lake subbasin, and Lower Mainstream subbasin were the most prominent. 2) The environmental pollution load situation in the YREB was generally stable and partially improved. High load level areas were mainly concentrated in the Yangtze River Delta Region and the provincial borders in upstream, midstream, and downstream areas. The high load level areas already formed in Chengdu and Chongqing were also the key regulatory points in the future. 3) The degree of local environmental pollution load was apparently affected by the adjacent cities. The population size, industrialization level, and the fiscal decentralization not only drove the increase of the local environmental pollution load level, but also affected the adjacent areas through the spatial spillover effects. The land development intensity mainly drove the increase in the local EPLI in the YREB. While factors such as economic development level and agricultural economic share could only act on the environmental pollution load process in adjacent cities. 4) According to the differentiation characteristics of drivers of each city, the YREB was divided into seven zones based on k-medoids cluster method, and targeted zoning control policy recommendations for alleviating environmental pollution load in the YREB were proposed. [ABSTRACT FROM AUTHOR]

It is of great significance and practical application value to extract land-cover type accurately. However, the input data usually used in classification such as reflectance data or vegetation index are very simple and quantitative remote sensing products are rarely used. In this paper, a multi-spectral land-cover classification method based on deep learning is proposed. Using the excellent detail capture ability of contourlet transform to obtain the potential information to supplement the spectral feature space, combined with deep learning for feature selection and feature extraction, a spectral–texture classification model is constructed. The multi-spectral sensing remote data and field measurement data in Dadukou District of Chongqing, northern Negev, and Changping region of Beijing were used for evaluation. Experiment results show the proposed method can outperform principal component analysis, linear discriminant analysis and neural network, and effectively improve the classification accuracy of multi-spectral images; this method provides a new perspective for land-use classification. [ABSTRACT FROM AUTHOR]

Landslides with large displacements are more dangerous than landslides with small displacements, because the first category causes more serious damages. In this paper, a new prediction method is introduced for rock planar slides with large displacements. The prediction model is not limited to a certain region but limited to a certain failure mechanism of a landslide. This case study was carried out in the red bed area, Nanjiang County, Sichuan Province, China, and validated in the red bed area of Yunyang and Fengjie Counties, Chongqing, China. The topographic factor T was proposed as a topographical indicator. The influence of the normalized rainfall R which is a combination of the duration of rainfall (D) and the average intensity (I) of rainfall was analyzed. A threshold value for rock planar sliding with large displacement was obtained by establishing a relationship between the T factor and the R factor. The primary probability factor P gives a final indication of the probability of rock planar sliding with large displacement. The prediction model is applied to the existing rock planar slides or the slopes with the presence of a number of preconditions for sliding. The prediction model obtained from Nanjiang County was validated successfully in the red bed area of the Yunyang and Fengjie Counties. It is assumed that the prediction model is suitable for other regions with a red bed structure as well. [ABSTRACT FROM AUTHOR]

This paper presents details of the recently reactivated landslide in Wushan Town, Chongqing, China. The landslide was reactivated on July 17, 2019, by slope cutting, and thereafter, entered a state of imminent sliding. The landslide involved 4 million m3 of rock and soil masses, thereby threatening National Road G348 and the safety of 588 residents in 136 households in Xiping Village and over 1000 residents in the Jinke Community. Field investigations, drilling, and in situ monitoring were performed to determine the landslide deformation characteristics and reactivation mechanism. The results show that the regional abundant rainfall, formation lithology, and tectonic effects were responsible for the formation of the ancient Baiyangwan landslide. Moreover, the building load on the rear and middle parts increased the sliding force. Open excavation at the toe decreased the anti-sliding force and directly promoted landslide reactivation. In particular, the groundwater table rise caused by gully filling in recent years also played a key role in the reactivation of the ancient landslide. [ABSTRACT FROM AUTHOR]

3D geological modeling data can only be measured rarely or indirectly, as it is necessary to interpolate the sparse and uneven geological data in the study area. Given the problems in the interpolation of data from different sources, we have introduced stratum interpolation and visualization technology based on the moving least squares (MLS) method and Poisson surface reconstruction method. The MLS method can not only obtain a smooth stratum surface by adjusting the relevant parameters of its interpolation, but it can also ensure the similarity of the stratum in space and the difference when far part. At the same time, it combines the Poisson reconstruction method and improves it, so that it can reconstruct the open surface by using a virtual outer frame from the original closed figure reconstruction theory. This paper takes the exploration line profile and geological boreholes in Xiushan County, Chongqing as an example, and visualizes them by fusion and the interpolation of data from different sources. The resulting stratum surface is smooth, continuous, accurate, and highly portable. [ABSTRACT FROM AUTHOR]

Assessment of the disaster resilience index (DRI) is an effective decision support tool for managing natural disasters. This study holds that disaster resilience is a dynamic process accompanied by coping capacity, adaptive capacity, and transformative capacity in different phases; therefore, we develop a three-dimensional capacity-based framework using seven indicators (including 38 subindicators) to map the multigoals for measuring resilience at the household level. Our data were acquired through questionnaire responses by 516 representative rural households in mountainous hazard-prone areas in Chongqing, China. The results reveal that more households are deemed "low resilience" and that geographical spatial differences exist in the DRI across the case regions. Several factors affecting the ability to survive, bounce back, and bounce forward from mountain hazards for rural households were found in China. The framework constructed in this paper offers a new perspective for a holistic understanding of disaster resilience. [ABSTRACT FROM AUTHOR]

The resettlement of residents to new urban areas in the Three Gorges Reservoir region, China, has generally adopted the local resettlement method, but engineering disturbances in conjunction with heavy rainfall have contributed to landslide instability. This paper discusses the influential factors and formation mechanism of the Jinjiling landslide in Jiangdong District, Wushan County, Chongqing, China. This study concludes that the cutting and filling of slopes have led to loading of the rear edge and open cut excavation at the downhill side of landslide. More importantly, the filling of channels with surface soil has blocked the surface water discharge channel along the landslide body, thereby transforming surface water into groundwater. Therefore, under heavy rainfall, the groundwater level in the Jinjiling landslide rose substantially, resulting in large deformation in approximately August 1, 2018. After emergency treatment, including groundwater pumping, the landslide deformation slowed considerably. The rising groundwater caused by filling of the slope was the key factor influencing the landslide. Based on the deformation characteristics and formation mechanism of the landslide, comprehensive control measures referred to as the "drainage+unloading+support" scheme are proposed, and drainage should be the focus of this type of landslide protection project. The results of this study may provide a reference for similar slope engineering projects. [ABSTRACT FROM AUTHOR]

This paper addresses the question of whether Chongqing's Red culture campaign (2008-2012) was a real mass campaign. Drawing upon Baudrillard's concept of simulation, it discusses the extent to which Chongqing's Red culture campaign can be characterized as the simulation of a traditional Maoist mass campaign. This paper argues that instead of being a real mass campaign, the Red culture program exhibited the following critical features of simulation-the procession of a model of the real, the liquidation of referentials, and the constitution of a self-induced and monolithic circuit of power. Firstly, the operation of Chongqing's Red culture campaign followed an established model of the ideal revolutionary mass campaign. The activities therefore did not follow their own trajectories but were organized to fit in the preexisting model. Secondly, the Red culture campaign was a process during which signs were emptied of their representational meaning. The definition of Red was expanded to include all songs that were considered 'healthy' and 'positive.' As a result, it stopped referring to any specific concept of political ideology. Thirdly, Chongqing's Red culture program demonstrated characteristics of a self-induced and nondialectical power circuit. The program did not exchange meaning with the audience of the program. Rather, the exchange of signs took place within the territory of an imagined singular political power. To think of the Red culture campaign not as a mass campaign but possibly the simulation of a mass campaign, this paper examines a distinctive set of power relations that were embedded in Chongqing's controversial political program and aims to facilitate a better understanding of the organization of political power in the current Chinese society. [ABSTRACT FROM AUTHOR]

This paper reports a geochemical study on the mineralogy and major elements of mid-ridge (A), near mountaintop (B), and valley (C) profiles developed in the Lower Cambrian black shale in Northeast Chongqing, China. The primary objective was to understand the elemental mobility, mineralogical transformation, and weathering progression during black shale chemical weathering in a subtropical climate. Profiles A, B, and C are characterized as weak, weak to moderate, and moderate to intense in terms of weathering intensity, respectively, by the Chemical Index of Alteration (CIA). Results indicate that most elements were mobilized by acidic solutions produced during the oxidation of pyrite and organic matter (OM). Among the major elements, Si was slightly enriched in profile A, but depleted through desilication in profile B and C. Al was enriched in the regolith zone in profile A and C, and Fe was enriched at the oxic front because of secondary clay and sesquioxide formation. The addition and depletion of major elements and the depth of the oxic front increased with the degree of weathering. Gypsum and Fe- (hydro-) oxides were observed to form and re-precipitate in the saprock and fractured shale zones. Clay minerals formed from dissolution of plagioclase and the transformation of other labile clay minerals during weathering. The progressive changes in mineralogical composition of weathered material from profile A to C showed the sequence of mineral decomposition with degree of weathering: first, oxidation of pyrite and OM; then Ca and Mg were removed during dissolution of carbonatite; followed by removal of Na from dissolution of plagioclase; lastly, transformation of clay minerals during weathering; meanwhile, desilication occurs at moderate to intense weathering stages. [ABSTRACT FROM AUTHOR]

Recent events have shifted the way the Chinese state responds to organized crime and corruption. The re-definition of organized crime, improved judicial oversight and the re-assessment of 'strike-hard' style police campaigns are key reforms. This paper discusses the recent changes in law, practice and oversight in the context of a brief overview of criminal groups in China and the Chongqing policing model. Revisions to the criminal law are described and the likely outcomes are assessed in the context of the key struggle to contain corruption and organized crime. [ABSTRACT FROM AUTHOR]

This paper describes a new method using water-silt composite blasting for tunneling and the field tests conducted in the Tieshanping tunnel, Chongqing City, China. In this method, water-silt composite is substituted for the traditional pure silt stemming of the blast holes. Because of the incompressibility of water, the attenuation of the blasting wave is postponed and the effect of the blast air extended. The water-silt blasting method resulted in a larger crack zone, improved the breakage of rock, reduced the rock heap, lowered the dust and saved explosive. The stability of the surrounding rock was studied using theoretical analysis, in situ measurements and numerical modeling. The measured displacement at the tunnel crown was in good agreement with the theoretical and numerical results. [ABSTRACT FROM AUTHOR]

As an important industrial city, Chongqing has experienced rapid economic growth in recent years, but at the same time the growth has been accompanied by serious pollution problems. Water quality monitoring shows that the waters of Chongqing are widely polluted. In this paper, the human capital approach is applied to assessing the economic losses and damages caused by water pollution in Chongqing. Based on previous studies and empirical investigations, water pollution-induced damage can be categorized into two general types; damage to ecosystems, including agriculture; and damage to non-ecosystems, including industry. The economic loss estimation of each type of the damage is conducted by taking into account a group of relevant parameters and methods. [ABSTRACT FROM AUTHOR]

Multiple carbonate cliffs are distributed in the karst mountain areas of southwestern China. The dynamic process and failure mechanism of rockfalls in the cliffs are complicated and undefined, and can be dangerous for settlements. Moreover, it is difficult to identify the potential for such failures before they occur. The rockfall of the Zengziyan cliff at Chongqing, China, is used as an example for studying this type of failure and to determine the developmental characteristics of rockfall, expounding on the evolving process from a cliff to an unstable rock mass through to rockfall. A fracturing–crashing failure mode is proposed, based on the evolutionary characteristics of damage development, compression-induced fracturing, rock mass crashing and overall rockfall. Finite difference numerical simulations were used to analyse and validate the failure mode of the Zengziyan cliff under three simulation conditions. The results of the simulations indicated that strength deterioration at the bottom of the cliff was the root cause of its fracturing–crashing rockfall. The outcomes of this paper could provide a new analytical model and theoretical basis for identifying and analysing similar types of geological disasters in the mountainous areas of southwestern China, and may provide valuable reference information for further mechanical analysis, stability evaluation and engineering prevention of unstable rock masses prone to a fracturing–crashing rockfall. [ABSTRACT FROM AUTHOR]