Landslide Remediation Research Articles

Uncertainty reduction strategies to enhance geotechnical site characterization: a case study of the red roof landslide in Wyoming

This study presents a method for identifying strategic locations to drill additional boreholes by quantifying and reducing subsurface uncertainties in geotechnical site investigations. The case study is the Red Roof landslide site located near milepost 140 on US Highway 26/89 in Teton County, Wyoming. A landslide remediation report had recommended additional boreholes before completion of the project. Two primary sources of uncertainty in geomaterials, namely geological and ground, are evaluated to determine the locations for these additional boreholes. The study aims to enhance site characterization and improve the accuracy of geotechnical assessments by strategically selecting and drilling additional boreholes that will reduce these subsurface uncertainties. The method involves reviewing and collecting the available site investigation data. An extensive geostatistical simulation is conducted based on the available data to identify spatial locations at the site that have uncertain subsurface conditions. Data from the additional boreholes could be utilized in these areas to reduce the uncertainty. This approach aligns with the current multi-phasing of site investigation in engineering practice, where a preliminary investigation is conducted before a detailed investigation. The results show that the locations of additional boreholes identified using this method differ from the ones earlier recommended, showcasing the effectiveness of the methodology in this application. This study also provides insights into effective strategies for reducing uncertainties through strategic borehole placement in similar geotechnical investigations. By quantifying geological and ground uncertainties, the method enables informed decision-making for slope stability analysis and risk assessment, with implications for infrastructure stability and geohazard mitigation.

Influence of complex engineering geological and geotechnical conditions on the selection of combined measures for road landslide remediation

Influence of complex engineering geological and geotechnical conditions on the selection of combined measures for road landslide remediation

Zhodnotenie dlhodobého monitorovania svahových deformácií a efektívnosti sanačných opatrení na zosuvnom území Nižná Myšľa

In 2010, extensive slope deformations were activated in Nižná Myšľa Village, which affected a large part of the village. Due to the extent of the affected area, the severity of the manifestations and especially the catastrophic consequences they caused in the built-up area of the village, the slope failures in Nižná Myšľa were evaluated as the second most destructive landslide event in the documented history of Slovakia. Almost immediately after the devasting event, a detailed engineering geological survey followed, which provided information on the extension, nature of slope deformations and became the basis for the design of the monitoring system. Monitoring activities have been ongoing since 2011 and continue to the present. By gradual upgrade of the monitoring objects network for monitoring subsurface deformations and for groundwater regime observations, a large data set was obtained over a longer period of time. Thanks to this, the Nižná Myšľa landslide area is one of the Slovak sites where the largest network of monitoring objects is built. At the same time by monitoring, the main activity took place – remediation of the geological environment in three successive stages. The aim of this work is to provide a comprehensive overview of the implemented remediation measures, an overview of dataset obtained from monitoring of slope deformations and selected environmental components, but mainly on the basis of these data, comprehensive evaluation of monitoring data obtained by monitoring and evaluation of the development of measured parameters with technical remediation measures. From the regularly repeated analysis of the parameters as well as from the evaluations results, the most significant results for the whole period of the site monitoring are the results of inclinometric measurements of total deformations and their increments for individual phases of measurement. The area is characterized by ongoing large-scale landslide activity, especially in the southern part of the village, which was also the most affected in 2010 and represents part of the central part of Nižná Myšľa, along with the northern part on the landslide from Staničná ulica Street, including the Elementary school area up to Hlavná ulica Street. In particular, remediation works during the first, second and third stages of the landslide remediation were directed to these areas. Despite a relatively large scope of remedy works and the evaluation of their effectiveness, the vast territory affected by slope failures was only partially rehabilitated depending on the approved funds. Therefore, even the remedial measures implemented so far are only partial, mainly in connection with the persistent movement activity in individual parts of the territory and should be completed according to the proposals from the geological works carried out and taking into account the results of monitoring. The basic objective should be a gradual implementation of remediation work so as to ensure the stability of the territory to the greatest possible extent, as ensuring the complete stability of the territory is technically and financially unrealistic due to its extent, complexity and slope deformation character. In the long term, redevelopment work needs to increase the territory’s ability to withstand similar adverse climatic events as occurred in June 2010.

LANDSLIDE REMEDIATION ON LOCATION ČOLE, THE SETTLEMENT ŽELJEZNO POLJE, ŽEPČE MUNICIPALITY

<p>The aim of this paper is to present a landslide's remediation conducted on the basis of research and testing of samples, and list those measures that will help to remediate the landslide or partially mitigate its further effects. These measures include: closing cracks, collecting and draining surface water from landslides, terrain planning, making supports from stone materials, drainage trenches, draining water from traffic areas, repairing water supply and sewerage systems, and establishing monitoring. The paper analyzes the phenomenon of instability and its causes, and presents the results of research at site in question before and after the remediation of instability. The geological profile and remediation methods will be determined after the presentation of the results.</p>

The Use of Soil Moisture and Pore-Water Pressure Sensors for the Interpretation of Landslide Behavior in Small-Scale Physical Models.

This paper presents some of the results and experiences in monitoring the hydraulic response of downscaled slope models under simulated rainfall in 1 g. The downscaled slope model platform was developed as part of a four-year research project, “Physical modeling of landslide remediation constructions’ behavior under static and seismic actions”, and its main components are briefly described with the particular focus on the sensor network that allows monitoring changes in soil moisture and pore-water pressure (pwp). The technical characteristics of the sensors and the measurement methods used to provide the metrics are described in detail. Some data on the hydraulic and mechanical responses obtained from the conducted tests on slope models built from different soil types under different test conditions are presented and interpreted in the context of rainfall-induced landslides. The results show that the sensor network used is suitable for monitoring changes in the soil moisture and pwp in the model, both in terms of the transient rainfall infiltration through partially saturated soil and in terms of the rise in the water table and pwp build-up under fully saturated conditions. It is shown how simultaneous monitoring of soil moisture and pwp can be used to reconstruct stress paths that the monitored points undergo during different test phases. Finally, some peculiarities related to hydraulic hysteresis and surface erosion that were observed in some of tests are discussed, as well as possible difficulties in achieving and maintaining the targeted initial moisture distribution in slope models.

LANDSLIDE REMEDIATION ON THE SCARP ABOVE THE LEVEL, ROAD M-17, SECTION: 007, TOPČIĆ POLJE – LAŠVA

<p>The aim of this paper is to present a landslide remediation based on research and testing of samples, and to list those measures that will help to remediate the landslide or partially mitigate its further effects. These measures include: closing cracks, collecting and draining surface water from landslides, terrain planning, making supports from stone materials, drainage trenches, draining water from traffic areas, repairing water supply and sewerage systems, and establishing monitoring. The phenomenon of instability and its causes has been analyzed, and the results of research at the subject site before and after the remediation of this instability will be presented and discussed. Geological profile and remediation methods will be determined after the presentation of the results.</p>

Application of the Multi-Criteria Optimization Method to Repair Landslides with Additional Soil Collapse

In current practice, the remediation of landslides has shown that the biggest problem is the increase in the number of works, and therefore the price of the works. This is due to several factors, including characteristic of the soil, such as the collapse (collapse) of the surrounding ground around the main slide during landslide remediation. Unless these soil erosion effects are taken into account, recovery costs will overrun, which can jeopardize the planned budget. This paper presents a multi-criteria optimization of landslide remediation using the PROMETHEE method and determines the optional number of walls for the additional soil erosion. In a case study on examples of real landslides in the Republic of Serbia, the application of the method is presented and appropriate conclusions are drawn.

ENGINEERING GEOLOGICAL AND GEOTECHNICAL CHARACTERISTICS OF LANDSLIDE IN GORNJI HRGOVI, MUNICIPALITY OF SREBRENIK

<p>Natural disasters during May 2014 caused a flood of water outside the unregulated bed of the river Tinja in the local area of Gornji Hrgovi. The flood effect affected the undermining and destruction of the foot part of the slope, reactivation and regressive development of the landslide, which was manifested by further secondary “breaking” of the sliding body towards the hypsometrically top part of the slope and intersection of the primary water pipeline. Gravitational displacement of the colluvial material resulted in significant degradation of the agricultural land surface in the central part of the unstable slope, while in the accumulation zone the accumulated slide mass destroyed the earth road communication. Based on the conducted geotechnical researches, determined engineering-geological and hydrogeological composition and properties of the terrain, the zoning of the terrain according to the degree of stability was performed, important recommendations and conditions of the landslide remediation method were presented.</p>

Landslide Susceptibility Mapping along Manipur-Assam NH-37

Landslides are a natural hazard in steep places that occur regularly and cause significant damage. To avoid and minimise hazards, comprehensive landslide remediation and control, landslide assessment, and hazard zonation are required. Various methods are established based on different assessment methodologies, which are essentially split into qualitative and quantitative approaches. GIS-based landslide susceptibility mapping was carried out along the National Highway 37, which connects Assam and Manipur and is a vital lifeline for the state, to identify and demarcate possible failure zones. A field visit was used to create a landslide inventory map along the road network. Google Earth and LANDSAT satellite imagery To perform landslide susceptibility zonation, thematic layers of several landslide causative elements were constructed in the study region. The study region has been divided into five endangered zones i.e. (“very low, low, moderate, high, and extremely high”). The landslide susceptibility zonation map was validated using the AUC and landslide density methods. The final map will be helpful to a variety of stakeholders, including town planners, engineers, geotechnical engineers, and geologists, for development and construction in the study region.

Monitoring and Data Analysis in Small-Scale Landslide Physical Model

Physical modeling of landslides using scaled landslide models began in the 1970s in Japan at scaled natural slope physical models. Laboratory experiments of landslide behavior in scaled physical models (also known as flume or flume test) started in the 1980s and 1990s in Canada, Japan, and Australia under 1 g conditions. The main purpose of the landslide physical modeling in the last 25 years was research of initiation, motion, and accumulation of fast flow-like landslides caused by infiltration of water in a slope. In October 2018, at the Faculty of Civil Engineering University of Rijeka, started a four-year research project “Physical modeling of landslide remediation constructions’ behavior under static and seismic actions” funded by the Croatian Science Foundation. This paper presents an overview of the methods and monitoring equipment used in the physical models of a sandy slope exposed to artificial rainfall. Landslide development was monitored by observation of volumetric water content and acceleration as well as by observations of surface displacement by means of high-speed stereo cameras, terrestrial laser scanning, and structure-from-motion photogrammetry. Some of the preliminary results of the initial series of experiments are presented, and advantages and disadvantages of the used equipment are discussed.

Evaluating Landslide Remediation Methods Used in the Carpathian Mountains, Poland

ABSTRACT The aim of this study was to evaluate the results of landslide remediation in the Polish Carpathians. The research for safeguarding the roads and infrastructure was conducted in the years 2005–2018 in nine landslide areas. The interpretation of engineering geology conditions was complex due to the soil-rock nature of the flysch sediment. Movements were activated after heavy rainfalls. In two cases, triggers were connected with the undercutting of the slope or external loading. The research methods included mapping, drilling, index, oedometer, direct shear tests, ground-penetrating radar scanning, and numerical modeling. To date, 15–59 series of inclinometer and piezometer network readings in 30 locations have been taken. Three online stations have been delivering continuous, nearly real-time data since May 2010. Displacements before the remediation ranged from a few millimeters to several centimeters. The proposed remediation methods included piles, micropiles, anchors, retaining walls, and drainage systems. Six stabilization projects were prepared and checked using the limit equilibrium method and finite element method modeling. The research shows that in five landslide areas, the proposed remedial works were effective. Two other partial stabilization works limited the scope of the movements but did not eliminate the risk. At two locations, only temporary repairs were conducted. Proper identification of the landslide triggers and activity is standard for the recognition of counteraction possibilities and could lower stabilization costs. The selected methods delivered data for remedial decisions. However, effective remediation of an active Carpathian landslide is difficult. It requires individually calibrated investigations, representative monitoring, and careful design of stabilization.

Detecting and monitoring long-term landslides in urbanized areas with nighttime light data and multi-seasonal Landsat imagery across Taiwan from 1998 to 2017

Monitoring long-term landslide activity is of importance for risk assessment and land management. Daytime airborne drones or very high-resolution optical satellites are often used to create landslide maps. However, such imagery comes at a high cost, making long-term risk analysis cost-prohibitive. Despite the widespread use of open-access 30 m Landsat imagery, their utility for landslide detection is often limited due to low classification accuracy. One of the major challenges is to separate landslides from other anthropogenic disturbances. Here, we produce landslide maps retrospectively from 1998 to 2017 for landslide-prone and highly populated Taiwan (35,874 km2). To improve classification accuracy of landslides, we integrate nighttime light imagery from the Defense Meteorological Satellite Program (DMSP) and the Visible Infrared Imaging Radiometer Suite (VIIRS), with multi-seasonal daytime optical Landsat time-series, and digital elevation data from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER). We employed a non-parametric machine-learning classifier, random forest, to classify the satellite imagery. The classifier was trained with data from three years (2005, 2010, and 2015), and was validated with an independent reference sample from twelve years. Our results demonstrated that combining nighttime light data and multi-seasonal imagery significantly improved the classification (p < 0.001), compared to conventional methods based on single-season optical imagery. The results confirmed that the developed classification model enabled mapping of landslides across Taiwan over a long period with annual overall accuracy varying between 96% and 97%, user's and producer's accuracies between 73% and 86%. Spatiotemporal analysis of the landslide inventories from 1998 to 2017 revealed different temporal patterns of landslide activities, showing those areas where landslides were persistent and other areas where landslides tended to reoccur after vegetation regrowth. In sum, we provide a robust method to detect long-term landslide activities based on freely available satellite imagery, which can be applied elsewhere. Our mapping effort of landslide spatiotemporal patterns is expected to be of high importance in developing effective landslide remediation strategies.

Patented inventions of Serbian scientists in the field of seismic reliability of structures and landslide remediation with application

Having in mind that on the territory of the Republic of Serbia patent protection of domestic inventions has been at the level of 20% of the total number of patents granted by the European Patent Office to inventors from Europe in the past twenty years in the area of seismic reliability of structures and landslide remediation, this work complements research on the continuity in the application of exceptional technical solutions of Serbian scientists in the field of civil engineering, that has been started with the work with title: Common characteristics of main contributions of Roger Boscovich, Milutin Milanković and Branko Žeželj to the development of civil engineering, 2017. Bearing in mind that Žeželj has been active in patent protection of his numerous inventions, during second half of the 20th century, this paper presents systematic overview of patented inventions created in 21st century by Serbian scientists and inventors in the field of seismic safety of structures and landslide remediation, as well as examples of their specific application.

Landslide and rockfall analysis of the western part of the Pavlov Hills in southern Moravia

My presentation is focused on the analysis and mapping of landslides and rock falls from the western part of the Pavlov Hills in southern Moravia. The Pavlov Hills are situated in the NW margin of the outer units of the Carpathian Flysh belt and are formed by Jurassic to Cretaceous flysh sediments incorporated into nape sheets of Carpathian Flysh Belt (Ždanice and Pouzdřany Units) (Poul 2006). Landslides are important elements in evolution of landforms and represent a serious geohazard in many areas of the world. Different kinds and types of landslides cause problems and difficulties to human society every year and that is why they are one of human treating natural disasters. There are only a few areas with recorded risks of landslides in the Czech Republic. One of these areas is the area of the Pavlov Hills. There is not enough of sufficient attention payed to geological mapping of the area of Pavlov Hills, because there are not many human settlements or infrastructure nearby. My field work involved observation and measurement of faults, rockfalls and slides. My presentation is focused on updating existing maps of slope instabilities in the mentioned area. For that reason, previously mapped areas were documented, registered and included into a map sheet. Eleven sliding localities in the Pavlov Hills were described and documented. Into the final map I included the additions according to type: flow slides – 5, planar slides – 4, and 2 rock falls. The resulting map with accompanying sheets can be used as a basis for further mapping or other activities associated with the observation of landslides such as landslide prevention and remediation, clarification of the hydrogeological conditions of the area and verification of geological slip surfaces, which are not affected by landslides.

Landslide Geohazard Monitoring, Early Warning and Stabilization Control Methods

Abstract This paper is a presentation of landslide monitoring, early warning and remediation methods recommended for the Polish Carpathians. Instrumentation included standard and automatic on-line measurements with the real-time transfer of data to an Internet web server. The research was funded through EU Innovative Economy Programme and also by the SOPO Landslide Counteraction Project. The landslides investigated were characterized by relatively low rates of the displacements. These ranged from a few millimetres to several centimetres per year. Colluviums of clayey flysch deposits were of a soil-rock type with a very high plasticity and moisture content. The instrumentation consisted of 23 standard inclinometers set to depths of 5-21 m. The starting point of monitoring measurements was in January 2006. These were performed every 1-2 months over the period of 8 years. The measurements taken detected displacements from several millimetres to 40 cm set at a depth of 1-17 m. The modern, on-line monitoring and early warning system was installed in May 2010. The system is the first of its kind in Poland and only one of several such real-time systems in the world. The installation was working with the Local Road Authority in Gorlice. It contained three automatic field stations for investigation of landslide parameters to depths of 12-16 m and weather station. In-place tilt transducers and innovative 3D continuous inclinometer systems with sensors located every 0.5 m were used. It has the possibility of measuring a much greater range of movements compared to standard systems. The conventional and real-time data obtained provided a better recognition of the triggering parameters and the control of geohazard stabilizations. The monitoring methods chosen supplemented by numerical modelling could lead to more reliable forecasting of such landslides and could thus provide better control and landslide remediation possibilities also to stabilization works which prevent landslides.

HORIZONTAL DRAINS AS EFFECTIVE MEASURE FOR LANDSLIDE REMEDIATION

Abstract Decrease of groundwater table level or decrease of buoyancy effects of groundwater is one of the most important landslide remediation measures. In Slovakia as well as in the world the horizontal drainage boreholes are often used for the landslide remediation. The article describes 40 years’ experience with use of the horizontal drainage boreholes in Slovakia, particularly in terms of their effectiveness and long-term functionality.

Stress Testing of Individual Steel Strands in a Multiple-Cable Single Borehole Anchorage for Geotechnical Engineering

Multiple-cable single borehole anchorages are widely used in China, accepted and regarded as a very effective method for slope protection, landslide remediation and foundation ditch support. This paper presents a new method for testing tensional stresses of individual steel strands within anchor cables in single boreholes. A rig has been designed to permit testing of cables within a single borehole, including two special features: a metal plate that distributes tension between strands of a cable and a sensing device that measures the stress in each individual strand. The feasibility of the method has been demonstrated by an in situ tensional stress test on anchor cables at a landslide remediation site that successfully measured the forces on individual steel strands fastened to different anchorage segments within a borehole. The steel cable strands displayed nonlinear extension characteristics; and the length of anchorage segments and grout strength met design criteria. The results confirm that this design of anchorage is satisfactory and can provide valuable data for future design and construction.

Landslides in Practice: Investigation, Analysis and Remedial/Preventative Options in Soils: (Derek H. Cornforth)

Dr. Derek Cornforth, who founded Landslide Technology in Portland, OR, in 1983, has turned more than 50 years of working with landslides into an excellent publication that will become the book used most by geologists and geotechnical engineers who perform landslide remediation and prevention. To date, it is the most complete and comprehensive text written on the practice of working with landslides. This book is written for the practicing engineer and geologist and for all students preparing to concentrate in this area. It will fast become the textbook of choice for graduate courses in landslides. I hope to start using it next year in my course! It should be found on the desk of everyone working with landslides because it contains so much information, it is so well organized which makes things easy to find, and it is well written! It should be purchased by all university libraries that have applied geology and civil engineering programs. I can also see the book being used by construction companies, land developers, landscape architects, and lawyers who work with the construction industry. Cornforth's book is divided into three parts. The first 12 chapters deal with investigations and analyses of landslides and the theory behind landslide work. Chapters 13 to 23 are the book's focal point and deal with all of the practical …

Drained Shear Strength Parameters for Analysis of Landslides

This paper presents recommendations for selecting the type and magnitude of drained shear strength parameters for analysis of landslides. In particular, the importance, existence, and use of the cohesion shear strength parameter is reviewed. For slope stability analyses, it is recommended that the shear strength be modeled using a stress dependent failure envelope or a friction angle that corresponds to the average effective normal stress acting on the slip surface passing through that particular material instead of using a combination of cohesion and friction angle to represent soil shear strength. Other recommendations for stability analyses include using an effective stress cohesion of zero for residual and fully softened strength situations. To facilitate selection of shear strength parameters for landslide analyses, empirical relationships for the drained residual and fully softened strengths are updated from the previous empirical relationships presented by Stark and Eid. Finally, the paper presents torsional ring shear test results that indicate that pre-existing shear surfaces exhibit self-healing that results in increased shear resistance. The magnitude of healing appears to increase with increasing soil plasticity, and this increase could have implications for the size, timing, and cost of landslide remediation.

The final remediation of the landslide Slano blato above settlement Lokavec at Ajdovščina

The remediation of such landslide as Slano blato more then 1300 m long and about 1.000.000 m3 of the volume, is very demanding. In the function of water contents the landslide behave as viscosious mud flow when the sliding masses are completely saturated with water or as a group of many classic soil landslides when saturation is not so high. From this conclusion the remediation has the main task to dry (or drain) soil material as much is possible. For the masses of about 200.000 m3 which slided into the valley near village Lokavec the only way of elimination of danger is removal and transport to the dump place, which was already done. Ali others measures as a part of final remediation are pushing of the sliding material from the main stream of the brook, building some smaller dams and making deep drain systems on the top of landslide. At the end regulation of brook through the gorge and surface planning with planting of the vegetation is necessary.