Slope Strengthening Research Articles

Analisis Penggunaan Tanaman Vetiver terhadap Stabilitas Lereng pada Bendungan Way Sekampung

Problems that occur in the western part of As Way Sekampung have the potential for landslides to occur. Efforts used to handle slope strengthening by planting vetiver plants. The research method used to analyze slopes uses the limit equilibrium method on slip surface sections using the Morgenstren-Price method with the help of Geostudio 2023.1.0 software. SLOPE/W to get the safety factor under normal conditions and under seismic load conditions. By using a seismic load with a return period of 500 years (PE 10% in 50 years) with a Peak Ground Acceleration (PGA) value for the Way Sekampung Dam inundation area of 0,265 g. In vetiver plants, the root depth is simulated according to the top soil depth of 0,0 – 0,1 m. Soil planted with vetiver plants experienced an increase in the value of cohesion (c) by 74,42% and a decrease in the value of the angle of internal friction (φ˚) by 49,40%. The conclusion obtained was that slope stability in normal existing conditions was 4,525 and in normal vetiver plant strengthening conditions the safety factor increased to 4,529. Then, in the existing seismic conditions, the safety factor is 2,624 and in strengthening vetiver plants with seismic loads, the safety factor value increases to 2,626. It can be concluded that vetiver plants are able to strengthen slope conditions.

Composite Materials as the Basis of Concrete Canvas

Statement of the problem. Composite materials based on mineral components and organic and mineral systems are gradually expanding their presence in the domestic market of materials and building techno-logies. Concrete fabric, as one of the varieties of textile-concrete, can be considered as a composite material whose properties depend both on those of polymeric materials that form its enclosing surfaces and those of the core material, and on the nature of the interaction between the facing and core materials. The purpose of the research presented in the article is to evaluate the main strength characteristics of the concrete canvas, as well as to study the effect of the content of Portland cement, plasticizer and modifying additive on the properties of fine-grained concrete as the basis of the concrete canvas, as well as to evaluate the possible areas of application of the concrete canvas with the obtained properties. Results. In the process of processing the results of the experiment and analytical optimization of the response functions, the fundamentals of the methodology for selecting the composition of modified fine-grained concrete as the basis of the concrete canvas were developed. As a result of the tests, the following characteristics of the material were established: average density ––1450––1500 kg/m3; compressive strength –– not less than 36––38 MPa, puncture strength –– not less than 3 kN; ultimate strength in ben-ding 16––20 MPa. Conclusions. Despite the fact that the thickness of the concrete canvas in the hardened state does not exceed 10 mm, its properties are not inferior to those of other types of textile concrete, i.e., they have high strength characteristics with a relatively small thickness. The most promising areas of application of the concrete canvas are the repair and waterproofing of reinforced concrete structures of hydraulic structures, and the strengthening of slopes.

Assessment of loess terraced slope erosion using unmanned aerial vehicle photogrammetry: Topographic and hydrological effects

AbstractTerraced slopes are widely used in the Loess Plateau to control gully erosion, yet their potential to induce new erosion patterns remains overlooked. Here we used unmanned aerial vehicle (UAV) photogrammetry to obtain centimeter‐resolution digital surface models (DSMs) and derived hydrological networks, slopes, aspects, and curvatures of the terraced slopes. Our analysis reveals terraces disrupted natural water pathways, spurring new rill formations during each rainy season—a process neglected by models. Intriguingly, despite gentler gradients, terraced slopes exhibited higher erosion rates than steeper gullies, with widespread rills on terrace ridges. Vegetation‐induced deposition surpassed erosion by 1.52 times, but moisture evaporation on sunny slopes limited plant growth and enhanced erosion. We propose targeted strategies tailored to these erosion mechanisms, including terrace redesign, runoff diversion, slope strengthening, and suitable vegetation, advancing sustainable land management. However, this study faces limitations due to the reliance on drone photogrammetry, which may be influenced by environmental factors like varying solar angles and vegetation growth, and the lack of extensive field validation to support the UAV‐derived data. Our study spotlights drone photogrammetry's potential for elucidating complex erosion dynamics on terraced slopes.

Landslide Management for Batu Tulis – Cross Bogor – Sukabumi Station Double Lane Project at STA 5+550

In the implementation of the St. Batu Tulis – Lintas Bogor – Sukabumi STA 5+550 project, a significant challenge arose with the occurrence of an avalanche during construction, attributing landslides to substantial land subsidence caused by the destabilization of the slope's soil or rocks. This disruption significantly impacted construction planning, particularly in terms of cost considerations. This study conducted a comprehensive comparative analysis of the stability of the original embankment slope and slopes reinforced with gabions (measuring 2m x 1m x 0.5m), sheet piles (type W-400 A-1000), and bored piles (size D600). To evaluate the stability, it was imperative to determine the safety factor (SF) and slope deformation under applied loads. The Plaxis 8.6 program was employed for the analysis, incorporating all relevant soil parameter data. Safety factor values were calculated as 1.67 for the gabion-bored pile combination slope, 1.62 for the sheet pile-reinforced slope, and 1.63 for the bored pile-reinforced slope. Estimated costs for slope strengthening were as follows: IDR 3,525,789,199.92 for sheet piles, IDR 2,180,309,258.00 for bored pile-gabion combination, and IDR 6,689,603,822.00 for bored piles alone. The budget for slope reinforcement with gabions proved more economical by IDR 1,345,479,941.92 compared to sheet piles and IDR 4,509,294,564.00 compared to bored piles. The reinforcement type selection was based on a cost analysis, prioritizing lower expenses while ensuring construction feasibility. Gabions offer advantages such as economical prices, flexibility, and simple construction methods, but they have drawbacks, including susceptibility of galvanized coated wire to water conditions with high salt or acid content and requiring a wide area for construction due to their large size. Sheet pile reinforcement is resistant to corrosion, durable, and has good performance, but it is unsuitable for supporting very high soil due to the requirement of a large cross-sectional area and not suitable for use in rocky soils due to piling difficulties.

SOIL SLOPE REINFORCEMENT USING CANTILEVER RETAINING WALL ON THE WEST RING ROAD OF SADAWARNA DAM, SUBANG DISTRICT

The research was conducted in the West Ring Road of Sadawarna Dam, Subang Regency. This research aims to provide recommendations for the design of cantilever retaining wall to increase the value of the slope safety factor in the research area. Calculation of the value of the slope safety factor uses the limit equilibrium method with the Janbu calculation method. In actual conditions, the value of the slope safety factor shows an unstable value referring to SNI 8460:2017, namely in static conditions with a vehicle load is 1.31 and in pseudostatic conditions with a vehicle load is 1.083. Slope strengthening was carried out using cantilever retaining wall. The retaining wall design that has been made meets the criteria for stability against overturning, stability against sliding, and stability for the bearing capacity of the soil. The safety factor value for slope with retaining wall shows a stable FS value referring to SNI 8460:2017, namely 1.53 in static conditions with vehicle loads and 1.11 in pseudostatic conditions with vehicle loads. Keyword: slope, safety factor, retaining wall, cantilever

Plaxis 2D Modelling of an Anchor Sheet Pile for Soil Slope Strengthening at Segamat, Johor

In soil engineering, the soil slope is one of the important issues in geotechnical and environmental engineering that can fail due to settlement behaviour. Due to soil slope instability, roads near the Segamat River’s slopes have seen severe settlement. Therefore, this study was carried out to determine how the geometry of the soil slope and the properties of the soil affect soil stability and deformation. Because of the varying slope geometries along the river, this study used two alternative slope geometries in its modelling. A comparison was made between the existing slope and the slope stabilised with sheet piling by using Plaxis 2D. Other parameters that affect slope stability are also being investigated, such as anchor length and anchor installation angle. The anchor sheet pile's presence is intended to improve the slope's stability. As a result of this analysis using PLAXIS 2D software, the optimal anchor length depends on the passive pressure of the soil behind the sheet pile. According to the results, installing an anchor with a 60° angle is more stable because the safety factor obtained is 3.26 which is greater than that of a 45° angle which is 1.33. It shows the anchor is the best support of the sheet pile for the soil slope stability.

Influence of Tea Plant Roots for Soil Slope Strengthening: Case Studies and Numerical Investigation

Influence of Tea Plant Roots for Soil Slope Strengthening: Case Studies and Numerical Investigation

LITHOLOGICAL AND MINERALOGICAL COMPOSITION OF ACCUMULATIVE BEACH SEDIMENTS OF THE DNIESTER-DNIPRO SEGMENT OF THE BLACK SEA

The article presents the results of studies of modern beach sediments of the northwestern Black Sea coast from the village of KarolinoBuhaz (Odesa oblast) to the village of Rybakivka (Mykolaiv oblast). The length of the coastal zone is about 110 km. Most of the beaches here are sloping beaches of various morphologies and widths. Using a uniform methodology, 64 samples were collected and processed along the entire profile. The sampling was carried out from the middle part of the beach strip between the water's edge and the shore in the summer in the absence of storms from a depth of 30 cm. The area of the sweep was 30×30 cm. Each sampling point was accompanied by a description of the geological structure, condition of the coastal zone and characteristics of the beach area. The sampling points were georeferenced using a GPS system. Grain size and mineralogical analyses were carried out, and the main patterns of lithological composition and distribution of mineral fractions along the entire profile were established. Several contrasting areas were identified: 1) Karolino-Buhaz-Chornomorsk, where the medium-grained (0.5–0.25 mm) fraction significantly prevails (67 %). In the sediments of this area, the main mineral of all fractions is quartz (90 %). The dominant heavy minerals are garnet, ilmenite, and magnetite; 2) Chornomorsk – Cape Velykyi Fontan and Lanzheron (Odesa oblast) – Kobleve (Mykolaiv oblast) with a significant content of coarse-grained psamite (2–1 mm) – 29 % and gravel (2–5 mm) – 16 % fractions. The main minerals here in all fractions are quartz and calcite; 3) Cape Velykyi Fontan -Lanzheron is characterised by a variable particle size distribution, with the bulk represented by fractions of 0.25–0.5 mm and 0.25–0.1 mm, which have different proportions on different beaches. The dominant mineral in all fractions is quartz, with calcite detritus present in subordinate amounts. Heavy minerals are represented by single grains of garnet, ilmenite, magnetite, staurolite; 4) Kobleve – Rybakivka (Mykolaiv oblast) with an increase in the content of fractions of 0.25–0.1 mm (up to 42 %). The main mineral in all fractions is quartz (up to 87 %). The secondary component is calcite detritus. Biotite, muscovite and tourmaline are notable impurities in fine-grained fractions. On some beaches located near the seaport of Odesa, numerous glassy spheroidal aggregates of various compositions and ferruginous spheroids have been found in fractions of less than 0.5 mm. In places of concentration of such formations, the colour of the beach sediments becomes grey. The total content of anthropogenic material in the beach sediments of the studied segment is on average 0.1–0.12 %. It increases significantly (up to 0.23 %) in the vicinity of the port of Odesa and adjacent areas. In addition, in contrast to the Danube-Dniester segment, there is a noticeable increase in the amount of large-sized material of man-made origin (plastic, concrete, bricks, wood fragments, metal, fabric, etc.) in the beach area. The main factor in the formation of the mineral and particle size distribution of beach sediments in the Dniester-Dnipro segment of the coast is coastal abrasion. The role of terrigenous inputs from the land is minimal and is manifested only in the northern part (Berezan Bay area). The formation of the material and fractional composition is significantly influenced by periodic artificial sand alluviation (beach area of the Odesa agglomeration), strengthening of slopes with concrete blocks, piling up of blocks of igneous and metamorphic rocks, mainly granitoid, breakwaters and other structures that change the direction and influence along the coastal currents.

Stabilization of Landslides Sliding Layer Using Electrokinetic Phenomena and Vacuum Treatment

The article presents the efficiency of application of cohesive soil dewatering for increasing its resistance to shearing, which influences the mass stability of flysch rock. Studies of the typical soil constituting the contact layer initiating the sliding of existing Carpathian flysch landslides were conducted. This aspect was examined because the water content of this soil decides its ability to form a sliding surface of the landslide block soil. The soil was subjected to changes in water content by dewatering with different methods. The influence of dewatering by self-acting gravitational outflow was examined and was additionally aided by two selected methods: electrokinetic phenomena and vacuum treatment. The model study conducted demonstrates the influence of the abovementioned dewatering methods on increasing the strength parameter of the soil at the contact layer in which sliding surfaces can be created. The paper also demonstrates the degree to which the application of the vacuum and electrokinetic treatment caused by DC current voltage influences the draining, decrease of plasticity, and increase of soil shear stress resistance. The application conditions and increase in effectiveness due to the application of the studied methods were determined. The proposed methods allowed for the strengthening of slopes for two exemplary landslides which formed in the area of occurrence of the Carpathian flysch.

Seismic performance assessment of a pile-supported wharf retrofitted with different slope strengthening strategies

Pile-supported wharves may be subjected to severe damage during major earthquakes. As such, efficient strategies for retrofitting wharf systems are needed. In this study, we investigate the seismic performance of a pile-supported wharf retrofitted by the following three conventional slope strengthening strategies: i) improving the ground with a soil-cement mixture, ii) driving pin piles near dike toe, and iii) creating an underwater bulkhead system using sheet piles. Effectiveness of the three retrofit schemes is assessed comprehensively. First, seismic response of the as-built and retrofitted pile-supported wharf is investigated. Subsequently, performance of the retrofit strategies in mitigating the seismic vulnerability is thoroughly investigated by comparing component- and system-level fragility curves. It was found that: (1) overall, the strategies are effective in mitigating the seismic response and in reducing the seismic fragilities of the wharf system; (2) the performance of the retrofit measures varies at the structural component level, as a retrofit measure may have an isolated local negative effect for a certain structural component. In this regard, an appropriate retrofit strategy should be identified based on specifically defined retrofit purposes; and (3) as implemented, the soil-cement mixture performed best (in lowering the system seismic fragility), followed by the pin pile, and lastly the sheet pile.

Optimizing the landslide-prone slope stabilization

Introduction. Nowadays, the study of landslide processes is one of the most intensive aspects of construction and maintenance of industrial and civil buildings and installations. The landslides violate the stability of foundations and entire complexes of installations, so the assessment of the stability of the slopes is the most important task before starting the construction. Currently, there is a large number of landslide classifications, which characterize the conditions of their formation, the history of geological development, their age, and structure. Normative documentation gives three ways of slope slump control: preventive, restricting, and liquidation ones. However, this source does not give systematic validity of the engineering solutions. The study sets the following tasks: to develop an algorithm for the optimal choice of rational slope strengthening in landslide construction conditions and to test it with a specific example.
 Materials and methods. The study analyzed the publications on theoretical and practical experience in dealing with landslides as well as normative documents. Numerical simulation methods were used to calculate the slope stability when testing the algorithm.
 Results. Using the introduced classification, the study presented an algorithm that makes it possible to choose a rational way of slope strengthening under landslide construction conditions. The concept of the algorithm allows step-by-step approximating parameters of a landslide-prone slope model to the real conditions, on the one hand, and selecting the most reasonable anti-landslide measures, on the other hand. The developed algorithm was tested on the territory of a large industrial complex situated on river overflood plain fringes. By applying the value engineering comparison of several slope stabilization variants, the research has taken the most optimal one of them for realization.
 Conclusions. The study developed the author’s classification and algorithm for the selection of optimal design solutions to stabilize landslide-prone slopes or slants. Successful approbation of the algorithm confirmed its practical applicability. The algorithm allows choosing the most effective complex for protection against landslides.

Pull Out and Creep Behaviour of Soil Nailing – A Case Study

The use of soil nails for slope strengthening is one of the popular methods since 1980s due to the attractive benefits of simple and fast installation method to reinforce cut slope. Proper assessment of the soil nail behavior between the nails and the surrounding soil will contribute to the safe and economical design of the reinforced soil structure. At present, the safety factor is adapted to soil nailing design and analysis, however, some soil nailed slope, which are designed, in compliance to the slope guidelines end up with failure. For the current knowledge, there is limited information on the loss of the shaft friction in soil nailing due to creep and the research on the behavior of the soil nail is also limited. Hence, in order to provide additional information on the behavior of the conventional soil nailing system, the bore holes and pull out test data were collected from the various projects: 1) Cheras, Kuala Lumpur, 2) Penang Hill, Penang, and 3) Kajang, Selangor. This study is focused on the behavior of the soil nail under pull out test at various types of soils and different soil nails characteristics. The parameters measured are soil nail pull out resistance and displacement of soil nails under different loading. In addition, the creep behavior of the soil nail was a study based on the displacement under maintain period at maximum test load during the pullout test. The creep behavior of soil nail is causing the loss of tension in the soil nail and that affecting the performance of the engineered slope. For the study and result presented, it is clear that soil nail under certain types of soil, especially dry, poorly graded cohesionless soils or soil with high water table is creep susceptible and had a lower pull out resistance. Pull out test on soil nail installed in medium stiff clayey Silt and sandy Silt and socketed in rock is performing up to design expectation.

Mesomechanics characteristics of soil reinforcement by plant roots

Vegetation for slope protection is widely used nowadays because of the role of plants in slope strengthening and environmental restoration. However, due to the lack of effective testing, root reinforcement in soil stability is mostly assessed in macroscopic mechanical analysis. This paper aims to investigate the mesomechanical characteristics of soil reinforcement with plant roots using a computed tomography (CT) triaxial compression apparatus. A series of unconsolidated-undrained CT triaxial compression tests of clay samples with and without Broussonetia papyrifera roots were conducted. By using CT technology, distinctive CT images and detailed CT data were obtained at different strains during loading. The soil crack data of CT images were then analyzed with MatLab. Finally, the evolution of internal structure of soil samples during loading was investigated. It indicated that the number, length, and width of cracks in the rooted soil samples evolved more slowly than those of the non-rooted samples during loading. In addition, it was observed that soil samples with thicker roots continued to bear loads even after local cracks appeared due to root bridging. In summary, at the mesoscopic level, the fact that roots inhibit further crack expansion and their bridging behavior helps increase the soil strength and toughness.

Application of Grid-Work Girders of Grouted Oblique Steel Pipe Piles for Reinforcement of Embankments with Slope Deformation Failure

In special situations, the treatment plan for embankment failure is hindered by cracking and sliding failure in highway embankment slopes. For example, the prestressed anchor cable or bolt frame beam is not suitable as the absence of a hard anchorage ground layer, or slip deformation embankment cannot be removed and rebuilt to protect the existing sub-grade. An ideal solution in this situation is to use grid-work girders of oblique steel pipe piles. The grouting of oblique steel pipe piles is a method that uses a composite foundation of steel pipe piles to reinforce slopes. Specifically, grout is embedded into steel pipe piles and passes through the sliding surface. Grouting can change deformable soil into composite soil and protect steel pipes from corrosion. Steel pipe piles serve as reinforcement by applying anti-slide force directly onto the soil. By means of a successful example of slope deformation treatment, this work discusses the scope of the application, the stress characteristics, the changes in slope stability, and the reinforcement effects after slope strengthening. The results would benefit engineering projects involving similar slope failure treatments.

Evaluation of the causes of Bukit Antarabangsa 2008 landslide by using fault tree analysis

Bukit Antarabangsa 2008 is considered as a deep-seated landslide which occurred in the landslide-prone area of Ulu Klang, Malaysia. The precipitation data obtained from previous studies show that there were comparatively less rainfalls immediately before the landslide which suggests that other potential triggers must be analyzed. This study analyses the causes of Bukit Antarabangsa 2008 landslide by performing fault tree analysis (FTA) which is a logical and diagrammatic method to evaluate the probability of an accident resulting from sequences and combinations of faults. The FTA is performed on four potential landslide contributors of improper shear strength parameters, flawed development plan, erroneous drainage planning & design and, ineffective slope strengthening works in order to determine the causes of the landslide. The analysis shows that the causes of Bukit Antarabangsa 2008 landslide potentially include ineffective slope strengthening works related to monitoring and maintenance which is followed by improper development plan having a probability of failure of 0.194 and 0.15 respectively. These causes actually correlate with the human errors which are often neglected during the slope construction and required to be addressed to increase the safety of the slopes.

Electrokinetic strengthening of slopes – Case history

Traditional embankment stabilisation techniques can have severe environmental impacts during construction and frequently leave behind a stark legacy of a bare embankment unsuitable for wildlife and unsightly for local residents. Electrokinetic geosynthetic (EKG) strengthening of slopes is a multi-component treatment method which includes dewatering by electro-osmosis; reinforcement; drainage and soil modification. The method offers economic and environmental benefits.This paper provides a brief review of the electrokinetic concept as it applies to failed slopes and illustrates the method with respect to the design, analysis, construction and verification of the stabilisation of a strategically important and environmentally sensitive highway embankment. The strengthening of the slope was achieved with a 29% reduction in cost and a 40% reduction in carbon footprint when compared to an adjacent embankment which had been remediated a year earlier using conventional soil nails. Following the repair the scheme was awarded an Institution of Civil Engineers Award for Innovation and a Green Apple Award for excellence in sustainable construction.

Features of cultivation Salix caprea for reconstruction of the landscape gardening heritage

Questions of cultivation Salix caprea L are taken up. For reconstruction of a landscape gardening heritage. The technology of cultivation of the given plant is developed for fast creation of green hedges and strengthening of slopes.

Slope Strengthening by Using a Grid Beam System

The evaluation of slope strengthening by using a grid beam system is carried out in this study by using a real slope existed in China is taken as the example to investigate the effects of the strengthening approach. The geological conditions of the example slope are introduced at first. The three dimensional element model of the slope is constructed with the aiding of the commercial package FLAC3D. The excavation process is simulated to obtain the stress distribution and displacement status. The slope performances without and with strengthening are numerical investigated and compared. The different bending moments of vertical beam of the frame and foundation pressure of slope reinforced with binding bolts, pre-pressed anchors and stress dispersion cables are computed. The made observations indicate that the stability of the slope has been obviously improved by applying the strengthening. The approach utilized in this study can also be adopted in the slope strengthening on the other sites.

Experimental study on the setting time of cement paste mixed with accelerating admixtures based on C3A

Setting time is a very important factor in terms of affecting the quality of tunnel lining and inclined slope strengthening. However, the quality criterion of the accelerating admixture (AA) used to improve setting time is not well established. In this study, methods of measuring the setting time of cement pastes with mixed AAs were evaluated using the Gillmore and Vicat needle test methods. It was found that for both test methods, regardless of initial and final setting, the setting time when the admixture was simultaneously added was faster than the post-addition method. For the Gillmore needle test method, two types of measurement methods were evaluated and it was observed that the setting time with cement type varied even when the same AA was used. Accordingly, manufacturing companies should develop AAs that are less influenced by cement type. For the Vicat needle test method, six types of measurement methods were evaluated and the following conclusions were obtained: (a) the temperature of materials should be controlled exactly and (b) to evaluate the performance of AA, an admixture usage of 5% (ratio of cement weight) was recommended.