Bridge Collapse Research Articles

Analysis of Flood Resistance of Masonry Arch Bridges Combining Numerical Simulation and Probabilistic Analysis

ABSTRACT In the context of global climate change, extreme weather events such as heavy rainfall and floods are becoming more frequent. The safety of masonry arch bridges is facing unprecedented challenges. This study aims to explore the collapse mechanism of bridges in flood environments by combining numerical simulation and stochastic analysis. Taking the collapse of the Original Zhenhai Bridge caused by heavy rainfall in July 2020 as a specific case, a three-dimensional numerical model is established to analyze the mechanical response of the bridge under the combined action of flood scour and water flow loads. Additionally, predictions of scour depth are made using both theoretical formulas and stochastic methods, comparing the impact of stochastic analysis on the mechanical performance of arch bridges under the same flood conditions. The study reveals that compared to pure scour, the structural characteristics of the bridge undergo significant changes under the coupled effects of scour and water flow loads. In extreme flood events, stochastic analysis has a significant impact on the structural safety under high flow conditions. The research results provide case references and scientific methods for the safety analysis of masonry arch bridges in flood environments.

Shear performance of horizontally curved steel box bridge girders under hydrocarbon fire exposure conditions: Numerical investigation and design implications

Recent fire incidents indicated that fire-induced bridge collapse is commonly associated with local shear failures occurred in web plates. However, current studies provided failure modes only related to deflection arose from steel bridge girders, irrespective of the underlying shear mechanism. To bridge the knowledge gap, this study presents an investigation on structural behavior of horizontally curved steel box bridge girders (HCSBBGs) under the combined effects of hydrocarbon fire exposure and shear-dominant loadings. The numerical models are developed utilizing the ANSYS program, incorporating a validated thermal-structural analysis model and a shear limit analysis model that accounts for web initial imperfections. These models are further employed to examine effects of fire-shear load scenarios, curvature radius, web slenderness ratio, and aspect ratio on shear performance of HCSBBGs. Herein, deflections, degradation of shear capacity, and web out-of-plane displacement (WOPD) of the steel box bridge girders are discussed in detail. Failure modes of steel box bridge girders can be determined via moment-shear interaction diagrams as specified by Eurocode 3 (EC3). The findings indicate that decreasing web slenderness ratio and web aspect ratio can enhance shear capacity of steel box girders. Further, shear failure modes are predominant when fire occurs near side support of HCSBBGs. Current fire-resistant design practices relying on deflection or flexural limit based failure criteria, cannot be applicable in predicting fire resistance of steel box bridge girders under shear failure mode. Therefore, a failure criterion based on the ultimate web out-of-plane displacement ratio (UWOPDR), related to the web shear limit state, can be more suitable for predicting fire resistance of HCSBBGs.

An adaptive fatigue crack growth model at the welded joints of steel bridge

Under the influence of random loads such as those from vehicles, the welded details in steel bridges tend to gradually develop into macrocracks, typically originating from manufacturing defects or stress concentration points. As the service life of the steel bridge increases, the continuous generation and propagation of fatigue cracks lead to a decline in the bridge's service performance, potentially resulting in catastrophic failures such as bridge collapse. Accurately analyzing the fatigue crack growth patterns at welded joints is a prerequisite for reliably assessing the structural service performance. The analysis of fatigue crack propagation depends on both the crack growth step size and the cyclic stress–strain response at the welded joint under loading. Considering the complexity of the material properties and stress concentration at the welded joint, which leads to a lack of analytical solutions for the cyclic stress–strain characteristics at the crack tip, numerical analysis was employed to obtain the cyclic stress–strain response at the crack tip of the welded joints. Using the size of the cyclic plastic zone at the crack tip as an adaptive crack growth step size, a model for fatigue crack growth was developed based on the plastic strain energy of the cyclic plastic zone. Fatigue test specimens extracted from the welded toe of cruciform welded joints were tested, providing cyclic stress–strain (Ramberg-Osgood material parameters) and fatigue damage characteristics (Manson-Coffin material parameters) of the material at the welded toe. High-cycle fatigue tests using cruciform welded joint specimens determined a good correlation between the crack propagation characteristic dimensions obtained from the adaptive numerical analysis model and the experimental results. The experimental findings confirmed the applicability of the established adaptive numerical analysis model for studying fatigue crack growth in cruciform welded joints. The parameters introduced in this model are physically meaningful, easy to obtain, and suitable for engineering applications.

Nonsurgical Correction of Surgical Rhinoplasty Complications with Hyaluronic Acid Fillers: A Retrospective Review of 2088 Cases.

Surgical rhinoplasty is a highly complex cosmetic procedure with significant revision rates. Unfortunately, surgical revision rhinoplasty is associated with many challenges. Nonsurgical correction of surgical rhinoplasty complications with injectable hyaluronic acid fillers is an alternative with less cost and downtime. In this article, we present the first author's experience with 2088 cases of nonsurgical revision rhinoplasty, including technical considerations, patient-reported outcomes, and adverse events. A retrospective chart review was completed on patients 18 years and older who received nonsurgical rhinoplasty treatment between March 2018 and August 2022. Patient demographic data, and data on indications for treatment, volume of filler used, patient-reported satisfaction, and adverse events (including erythema, infection, vascular occlusion, and necrosis) were collected up to 1 year after the initial injection. A total of 2088 patient cases are included in this study. The most common indications for treatment included bridge collapse or asymmetry (49.0%), an under-projected tip (44.0%), and surface irregularity/scarring (35.4%). The mean volume of filler used at initial treatment was 0.49 mL (SD 0.19). Median patient satisfaction immediately after treatment was 9 (visual analog scale ranging from 1 to 10). The most common adverse event reported at the 2-week follow-up was erythema (36.4%). Three patients presented with skin necrosis (0.47%). All three of these were transient and self-resolving. Nonsurgical correction of rhinoplasty complications with hyaluronic acid fillers can be a safe, minimally invasive option with high patient satisfaction and immediate and predictable results. This should be considered first line before surgical revision.

The Impact of Flow Patterns Due to the Cold Lahar Flooding of Mount Semeru on the Collapse of the Bridge Connecting Malang District and Lumajang District

The flow patterns that occur in rivers as a result of falling cold lava often cause damage here and there. This incident cannot be separated from the large volume of water mixed with material that crosses the open channel which is caused by input water supply or water supply from river reservoirs crossed by cold lava. by water researchers for water mixed with volcanic eruption material suspended above. The event of water flowing through a river is influenced by the presence of the surface profile of the river bed and the various widths of the river that occur. If a volume with a certain viscosity is given, a thick flow will be formed that can be seen on the surface of the river, while that which is not visible to the naked eye above the water surface is called thick viscosity. If the runoff of cold lava material that occurs in the channel is not measured, it will result in wild jumps. The wild and viscous jumping structure that has been arranged can be observed as to how the flow pattern occurs. To avoid not detecting the flow pattern, water measuring structures are needed, one of which is a threshold with openings below or what is known as flow above the threshold along with existing bridge buildings around it. This sluice gate is easy to operate manually. The need for water operations with excess water availability is not an easy thing to calculate, because of the influence of depth and jumps that occur around the bridge, hydraulic jump patterns often ignore this measurability, this will be an obstacle if there is a large supply of cold lava. mixed with rainwater during peak conditions in the drainage process. Observations of this completion need to be proven by carrying out model tests using a tool known as the Threshold which produces a water jump along with the material. This requires further investigation for research in the model channel. For modeling thresholds and bridges connecting between plains, this tool provides instruments and many threshold treatments as well as regulating pressurized water with a pump at a certain flow rate in a measurable manner. To analyze the height of building damage, determine the flow pattern, speed by observation, test results with valve openings on certain pumps, researchers tested and measured the position of cold lava deposits one by one, the position of the slope of the river in certain sections, starting with an opening of 0.5; 0.75, read the instrument, move the threshold position from a bridge distance of 20 cm, 40 cm, to the furthest distance of 240 cm. Make graphs of test results for the threshold of the bridge opening transfer tool by testing the tool and opening 3 times for each pump opening, recording, mapping the depth values, jump length and travel time of the instrument on the test tool. Recommend the results of the analysis of the Threshold and Bridge tests to provide information to bridge construction planners that the test results with various threshold positions in certain conditions have the value of the Glidik II bridge collapse, the jump with the travel time of the speed of passing cold lava. Next, the bridge is determined and the next threshold can be used to determine how severe the damage is to the river. This research is laboratory research with threshold and bridge models. The target of this output is a journal article resulting from a simulation of determining the flow pattern that occurs in the channel by shifting the position of the threshold relative to the location of the bridge from the channel model with various diameter sizes of the model material, the results of which are in the form of a table and graphed on the part modeled in the water laboratory, especially flow with sediment and cold lava material. The results of this section were observed up to the collapse of the bridge at a depth of 4.5 cm with an opening of ½ second to 37 (on the model scale) observed or a depth of 45 meters (on the empirical scale). to then be written in the form of an article to be included in an international journal.

Dynamic behaviors of bridge with corroded RC piers under barge collisions

Reinforced concrete (RC) bridge piers located in navigable waterways are susceptible to chloride-induced corrosion, which may cause severe damage or even entire collapse of bridge under potential barge collisions. The present study aims to examine the failure patterns and dynamic responses of typical simply supported girder bridge with corroded RC piers under barge collisions. Firstly, nine RC column specimens with three designed corrosion degrees and two corrosion strategies were prepared using the impressed anodic current technique. Secondly, the drop hammer impact and axial compression tests were successively performed to examine the residual axial load bearing capacities of both unimpacted and impacted specimens. Furthermore, by comprehensively considering the effects of corrosion-induced deteriorations on the effective cross-sectional area and yield strength of reinforcements, concrete strength, as well as the rebar-concrete bond-slip relationship, the refined finite element (FE) models of specimens were established and validated. Finally, the dynamic behaviors of a prototype simply supported girder bridge with corroded RC piers under barge collisions at different service lives, i.e., 0–60 years, were numerically assessed. It indicates that: (i) under drop hammer impact, six specimens all exhibit global flexure failure, and relatively severe concrete cracking and spalling occur in the specimens with 15 % designed corrosion degree; (ii) the axial load bearing capacities of specimens with 5 % and 15 % designed corrosion degrees are reduced by 15.46 % and 34.86 % compared to the unimpacted non-corroded specimen, and 11.29 % and 43.30 % compared to the impacted non-corroded specimen; (iii) the transverse impact resulted in 25.93 %, 22.27 % and 35.53 % reductions in axial load bearing capacities for 0 %, 5 % and 15 % designed corrosion degree, respectively; (iv) for the prototype barge-bridge collision scenario, the failure patterns vary from minor bending cracks to remarkable flexural failure as the service live increases from 0 to 60 years. The corrosion-induced degradations of bridge performance should be concerned for the vessel collision-resistant design of bridge.

Real-time prediction and detection of contacts between vessels and facilities based on AIS: A multivariate time-series classification approach

Contact casualties between vessels and fixed facilities, such as the recent Baltimore bridge collapse, occur frequently in port areas and narrow waters, resulting in significant losses in property and operational efficiency. However, manual reporting of such contacts is typically prone to errors and delays, while automatic prediction and detection of such contacts remain unresolved. To this end, this study proposes a real-time contact prediction and detection method, powered by multivariate time-series classification and Automatic Identification System (AIS) transmissions. In the off-line training procedure, the historical AIS records are processed into time-series sequences containing five dimensions (i.e., distance to ground, heading, speed over ground, course over ground, navigational status). An LSTM-based classifier is built and trained upon those sequences to differentiate patterns between contact casualties (i.e., positive-class) and normal operations (i.e., negative-class). In the on-line detection procedure, the latest transmitted AIS records are fed into the trained classifier, where the contact casualty is predicted, detected and reported in a real-time manner. A dataset encompassing worldwide AIS records of 150 reported contact casualties and 150 normal operations dated from 01/01/2023 to 31/12/2023, is constructed for method training and validation. Upon comparison, the proposed method outperforms state-of-the-art baselines by achieving the highest F1-score (0.9512), accuracy (0.9500), and AUC (0.9557). It timely predicts and detects 28 out of 30 contact casualties, while the remaining two casualties are detected with a slightly delay, demonstrating high feasibility for real-world application.

Seismic vulnerability assessment of RC deck-stiffened arch bridges

Due to the recent damage and collapse of several bridges in Italy, reliable quantification of their vulnerability is paramount for planning various risk mitigation and resilience-enhancing strategies. This paper specifically focuses on the seismic vulnerability and loss assessment of existing reinforced concrete (RC) deck-stiffened arch bridges. The study considers a bridge typology known as the “Maillart–type” arch bridge, a common structural typology in the 1950s and characterised by a particularly stiff deck and a slender vault, i.e., a high deck-to-arch flexural stiffness ratio. Such bridges were typically designed considering only gravity loads and usually without ductile structural detailing and consideration of capacity-design principles. Historical documents and original design blueprints are used to simulate the design of an archetype bridge representative of the Italian “Maillart-type” arch bridge population. Then, nonlinear cloud-based time-history analysis is performed to investigate the seismic response of the considered archetype under varying ground-motion intensities and derive fragility and vulnerability relationships. Specifically, three different models are considered: one that adopts a conservative approach where damage is determined by the shear failure of the shortest pillar, another that provides a more detailed representation of structural damage progression, and a third that assumes retrofitting of the shortest pillar. The vulnerability relationships are combined with site-specific seismic hazard curves for case-study locations to estimate expected annual losses. The results represent a first step in assessing the seismic vulnerability of “Maillart–type” arch bridges to plan seismic risk mitigation interventions for such a bridge typology.

State of the Art on Forensic Bridge Engineering in Chile. A Management and Technical Overview

Chile is a country highly affected by natural hazards, especially scour and seismic phenomena. Therefore, throughout the twentieth century and the beginning of the twenty-first, total or partial collapses of bridges have been evidenced, particularly those that occurred in the 1960 and 2010 earthquakes. From these experiences, the Chilean Highway Administration has promoted a series of management activities in order to reduce the number of collapsed structures. In this context, since 2019 the Ministry of Public Works of Chile (MOP) supported by the Chilean universities started a program to develop the subject of forensic engineering on bridges, in order to include the methodology in the technical codes and provide a standardization of protocols for the implementation of activities in the case of the collapse of structures. The aspects included in this methodology are: Determination of volatile and non-volatile information; Actions for intervention on the structure and protection of users; Gathering of technical information through the application of tests; Review of stress–strain states through Finite Element Method (FEM); Elaboration of hypotheses and review of them through a decision tree; and, finally, Conclusions and recommendations from a technical and contractual perspective. This paper presents a detailed description of the current forensic engineering methodology in Chile and its first application in the Cancura Bridge case study. In addition, a historical compilation of Chilean bridge collapses is presented, in each case identifying the typology of the structure, the causes of collapse and the main inspection techniques used. Finally, a statistical review is carried out analyzing aspects such as stages of the life cycle where collapse has occurred: design, construction or operation, and the incidence of natural hazards in these phenomena. From this analysis, the cases of Loncomilla, Cancura and Huasco bridges are highlighted. Since the collapse of these bridges occurred without the implementation of current methodology, the article concludes on the advantages and disadvantages of the methodology, providing a comparative analysis with the inspection activities in these structures.

ArchIMEDES: Computer Vision Tracking of the Inherent Changes to Structural Stability of Masonry Arch Bridges Resulting from Increased Bed Scour.

Scour-induced failure of masonry arch bridges is a common cause of bridge collapse, especially during extreme flood events. Over recent years there has been a significant increase in the numbers of documented scour induced failures of this bridge stock across Europe and the USA. The extent of the scour can erode the supporting soil or sediment around the bridge piers or abutments, leading to a loss of support for the structure. As the foundation becomes unstable, it can result in settlement or tilting of the bridge, potentially causing structural damage, while the ongoing nature of scour can result in the progressive deterioration of the bridge’s ability to safely transfer load. Traditional hydraulic adjustments, such as streamlining abutments with wing walls and using cutwaters on piers, do not significantly reduce scour depth for masonry arch bridges. This paper presents initial findings of an investigation that links the changes of response in load carrying capacity to the easement of support at the bridge foundation due to scour. Scale experiments on the FlexiArchTM under loading with realistic scour conditions is contributing to the development of an algorithm based on the relationship between the structural response of the FlexiArchTM and prevailing scour conditions. The computer vision-based monitoring package ArchIMEDES, developed as part of the research, will use this algorithm to predict current bridge scour conditions at any given time. This will allow for potential scour development to be identified and investigated before the bridge collapses, ensuring the security and safety of these vital pieces of infrastructure.

Comparison of anomalous displacement detectability of bridges between X and C band InSAR data: Case study on a collapse of water pipe bridge

This paper presents a feasibility of detecting anomalous displacements on bridges where collapses have occurred using C-band satellite synthetic aperture radar (SAR). Recently, the number of aging bridges due to damage and corrosion has been increased in many countries. Although there are various maintenance and management systems, the authors have focused on satellite SAR, one of the remote sensing technologies, to establish a wide-area multiple bridge monitoring technology. In a previous study, the authors analyzed high-resolution X-band interferometric SAR (InSAR) data acquired by the Italian satellite COSMO-SkyMed during the two years before the accident for the MUSOTA water pipe bridge in Japan, which collapsed on October 2021. As a result, it was shown that there was an anomalous displacement about one year before the accident, which seemed to be a sign of the collapse. On the other hand, the utilization of Sentinel-1 (C-band) data, which has lower resolution than X-band data, but is freely available, covers a wide area, and has dense time-series SAR images, would be beneficial for the practical application of this technology. In this study, InSAR data acquired by Sentinel-1 for the MUSOTA water pipe bridge from 2016 to 2022 are analyzed. Then, we compare the line-of-sight (LOS) displacement anomaly before the collapse with the results analyzed by the X-band satellite. As a result of statistical analysis of the displacement between the collapsed span and the adjacent spans with similar structural type assumed to be intact, it is shown that Sentinel-1 also captured differences which seemed to be the signs of the collapse about one year before the accident. This result supports the analysis of the X-band satellite data and shows potential for utilization in bridge anomaly detection systems, even for low-resolution C-band data.

Detailed analysis based on vertical and longitudinal deformations estimated from InSAR displacement by data assimilation

Application of a SAR satellite to Structural Health Monitoring (SHM) has attracted much attention due to its high efficiency. SHM using a SAR satellite doesn’t require installation of sensors and has the capability of monitoring wide area. However, the displacement obtained by a single SAR satellite is line-of-sight displacement which is not either vertical or longitudinal displacement. Thus, it is not easy to interpret line-of-sight displacement. This paper aims to solve this problem. The objective of this paper is to estimate longitudinal and vertical displacement from line-of-sight displacement and to analyze in detail a fallen water pipe bridge. For estimation of longitudinal and vertical displacement, data assimilation is employed. As a result of data assimilation, successfully observed line-of-sight displacement is reproduced. Negative correlations between displacements at piers and temperature are observed. A year prior to the bridge collapse, anomalous displacement pattern is observed at the centre of the span. In addition, deformation caused by damage is observed.

Tools Used from Mathematics in The Study of a Riemannian Wave Equation to Prevent the Collapse of Bridges

Tools Used from Mathematics in The Study of a Riemannian Wave Equation to Prevent the Collapse of Bridges

Probabilistic seismic demand of typical highway bridges in moderate-intensity zones

The probabilistic seismic demand for typical highway bridges in moderate-intensity zones is investigated. The seismic demands and infrastructure destructions are severe on critical bridge components during and after seismic activity in moderate-intensity zones. This article aims to determine seismic demand, predict the probabilistic seismic demand model (PSDM), and identify the interdependence of bridge components. Based on bin-ground motion, 154 analytical bridge-ground motion samples are prepared to record output data using nonlinear time history analysis (NLTHA). High-level ground motion duration and peak ground acceleration are used to measure the seismic demand and intensity of the bridge. The best-fitting lognormal distribution and correlation coefficient between demand in the transformation states are analysed to indicate the interaction between the two at dissimilar levels of interdependence. As a result, bearing pads on all abutments, the bearing pad on pier-1, and the shear key on pier-2 are best fitted with a high level of interdependence to design the seismic performance of highway bridges. Therefore, the ground motion characteristics play a vital role in the infrastructure collapse of the highway bridges in the moderate-intensity zone and should be held in high regard.

Suspension Bridge Estimation Method using the Fokker-Planck Model

The failure of the suspension bridge has been known since the beginning of the bridge collapse. Most of these failures form the basis of current engineering knowledge. One of the factors of failure is human-made factors related to the calculation of the bridge estimate. This paper presents an indirect estimation method using numerical simulation using finite elements by analyzing the Fokker-Planck model when dynamic excitation is associated with bridge loads. The results show that the Fokker-Planck model's homogeneous form can take into account the solution for the bridge analysis approach. It leads to a stable state when giving mass variations to the model. The indirect estimation method using finite elements can estimate the cable tension with controllable weak damping. It can be concluded that the method in this study is more accurate and convenient for the application technique.

Comprehensive Safety Strategies and Innovations for Infrastructure Resilience in Bridges

This study explores the critical elements of ensuring bridge safety, covering design, construction, maintenance, personal protective equipment (PPE), community engagement, and public perception. It draws lessons from historical bridge failures, like the Morandi Bridge collapse, highlighting the necessity for stringent safety protocols in infrastructure development. Innovative solutions, such as heating systems to prevent ice formation and seismic resilient designs, are explored to address maintenance challenges and environmental impacts. In addition, the study also examines the role of public perception, education, and community engagement in bridge safety. It discusses the positive and negative aspects of safety measures like nets and Fall Protection Systems (FPS) and evaluates the impact of public education programs on safety awareness. Visual standards, clear signage, and innovations in bridge design, such as smart sensors and self-healing materials, are explored for their contributions to safety and longevity. A comparative analysis of safety standards worldwide, such as AASHTO, BSI, CSA, Austroad, Eurocodes, JRA, TB, IRC, ABNT, and SANS, highlights global efforts to establish consistent safety measures. Historical data and case studies, including the Tacoma Bridge Collapse and the Minneapolis I-35W Collapse, provide insights into safety measures' evolution. In conclusion, there is a need for a comprehensive approach to bridge safety, on the backend by implementing policies and ensuring safety protocols are being met, as well as a good public perception using visual components, like safety nets. Success hinges on collaborative efforts, robust risk reduction, and fostering public confidence in infrastructure development.

Factors influencing suffusion-induced delayed displacement of river bridge piers

In recent years, local scour has occurred on the pier foundations of river bridges during heavy rain and river flooding, often resulting in bridge collapse and outflow. This study focused on the characteristic displacement, called “delayed displacement”, of the river bridge pier. The critical displacement of the piers was first observed several days after the flood when the train passed and not immediately after the flood. The authors hypothesized that one of the possible reasons for the delayed displacement is the suffusion of the supporting ground beneath the pier foundation during the flood, followed by a compressive behavior due to the collapse of the soil skeleton under repeated traffic loads. Accordingly, this study performed erosion tests simulating flood and cyclic loading tests simulating train passage using a triaxial test apparatus to check the validity of this hypothesis. In some test cases, suffusion without any deformation occurred in the erosion test but deformed in the cyclic loading test just after the erosion test. This behavior matches the behavior of delayed displacement. It was also suggested that the risk of the delayed displacement becomes high when the soil skeleton was assumed to primarily comprise fine particles, and the void ratio and hydraulic gradient were high. By contrast, when the soil skeleton was assumed to primarily comprise coarse particles, suffusion occurred in the erosion test, but did not deform in the subsequent cyclic loading test. Thus, the risk of delayed displacement is considered to be low when coarse particles are dominant. Furthermore, clear relationship between suffusion and the consequent reduction in soil stiffness cannot be observed. This result indicates that no significant change in the stiffness occur in the supporting ground of the pier foundation at the stage immediately before the delayed displacement. Thus, identifying the deterioration in the stability of the piers through impact loading test, which is based on the concept that local scour reduces the natural frequency of the bridge pier, is difficult.

Viewpoint: The Baltimore bridge collapse: a vital lesson for structural engineers

The tragedy of the Francis Scott Key Bridge highlights the need for structural engineers to ensure that the risks inherent in our built infrastructure remain acceptable, argues Colin Caprani.

Sedimentation Management Good Practice (SMGP) to Manage Sedimentation at Kawanua Flood Disaster, Seram Island

Flood natural disasters are almost certain to occur every rainy season. Rain with very high intensity occurred on July 9th, 2023 causing an increase in water discharge which made the river overflow and the Kawanua Bridge collapse. In the upstream area of the river, there is Kawa check dam which has experienced a huge amount of sedimentation due to the top of the crest check dam being covered by fallen trees. This study aims to determine the magnitude of the rate of erosion and sedimentation that occurs in the catchment area in the upper reaches of the river and find out where the source of sedimentation comes from, then the most appropriate solution can be decided, and a similar disaster does not occur. This research used a USLE method to calculate the erosion and sedimentation rate. The results showed that 37.88% of the catchment area was classified as a low level of erosion. Meanwhile, the moderate level of erosion represented 29.42%. Sedimentation Management Good Practice (SMGP) is a concept used to analyze erosion and sedimentation problems. The recommendations given by the SMGP concept have sustainable characteristics that minimize damage to the water environment. Additional recommendations are given by collaborating between government institutions related to catchment area and forest area management authority.

CROSS Safety Alert: Lessons learned from the 2018 Florida bridge collapse during construction

This month we present key elements of a CROSS Safety Alert from December 2020 detailing the failures and lessons learned from the Florida bridge collapse in 2018.