Slope Stability, Retaining Walls, and Foundations

2009 ◽  
2020 ◽  
pp. 65-75
Author(s):  
Liudmyla Skochko ◽  
Viktor Nosenko ◽  
Vasyl Pidlutskyi ◽  
Oleksandr Gavryliuk

The stability of the slope in the existing and design provisions is investigated, the constructive decisions of retaining walls on protection of the territory of construction of a residential complex in a zone of a slope are substantiated. The stability of the slope when using rational landslide structures is estimated. The results of the calculation of the slope stability for five characteristic sections on the basis of engineering-geological survey are analyzed. For each of the given sections the finite-element scheme according to the last data on change of a relief is created. The slope was formed artificially by filling the existing ravine with construction debris from the demolition of old houses and from the excavation of ditches for the first houses of the complex. Five sections along the slope are considered and its stability in the natural state and design positions is determined. Also the constructive decisions of retaining walls on protection of the territory of construction of a residential complex as along the slope there are bulk soils with various difference of heights are substantiated. This requires a separate approach to the choice of parameters of retaining walls, namely the dimensions of the piles and their mutual placement, as well as the choice of the angle of the bulk soil along the slope. The calculations were performed using numerical simulation of the stress-strain state of the system "slope soils-retaining wall" using the finite element method. An elastic-plastic model of soil deformation with a change in soil parameters (deformation module) depending on the level of stresses in the soil is adopted. Hardening soil model (HSM) used. Calculations of slope stability involve taking into account the technological sequence of erection of retaining walls and modeling of the phased development of the pit. The simulation was performed in several stages: Stage 1 - determination of stresses from the own shaft, Stage 2 - assessment of slope stability before construction, Stage 3 - installation of retaining wall piles, Stage 4 - assessment of slope stability after landslides. Based on these studies, practical recommendations were developed for the design of each section of the retaining wall in accordance with the characteristic cross-sections.


Author(s):  
Rizki Ramadhan ◽  
Munirwansyah Munirwansyah ◽  
Munira Sungkar

The Aceh Tengah / Gayo Lues-Blangkejeren road segment (N.022) Km 438 + 775 is one of the Central Cross National Roads in the Province of Aceh, which often experiences landslides due to being in hilly areas. Landslides that occur in these locations are caused by scouring of road runoff, lack of optimal drainage and the absence of outlets for drainage and soil layers under asphalt pavement consisting of loose material. Therefore, a slope reinforcement study with Counterfort type retaining wall is needed. This study aims to analyze slope stability by obtaining safety factor numbers and identifying slope failure patterns. Analysis was carried out to obtain safety factors and slope failure patterns by using 2D Plaxis and slice methods. The calculation of safety factors for Counterfort type retaining walls is done manually. The input soil parameters used are dry volume weight (gd), wet volume weight (gw), permeability (k), modulus young (Eref), paisson's ratio (υ), shear angle (f), cohesion (c) . The results of slope stability analysis on the existing conditions using the Plaxis program and the slice method with radius (r) 65.06 meters found that safety factors were 1.038 and 1.079 with unsafe slope conditions (FK <1.25). The results of the analysis after reinforced counterfort and minipile type retaining wall with a length of 12 meters found 1,268 safety factor numbers with unsafe slope conditions (FK <1,5). Thus, additional reinforcement is needed by using anchor on the counterfort. The results of slope stability analysis after reinforced counterfort, minipile and anchor type retaining walls with a length of 20 meters and a slope of 30 ° were obtained with a safety factor number of 1.513 with safe slope conditions (SF> 1.5).ABSTRAKRuas jalan batas Aceh Tengah/Gayo Lues-Blangkejeren (N.022) Km 438+775 merupakan salah satu ruas jalan Nasional Lintas Tengah Provinsi Aceh, yang sering mengalami terjadi tanah longsor karena berada di daerah perbukitan. Longsoran yang terjadi pada lokasi tersebut disebabkan oleh gerusan air limpasan permukaan jalan, kurang optimalnya drainase dan tidak adanya outlet untuk pembuangan air serta lapisan tanah di bawah perkerasan aspal terdiri dari material lepas. Oleh karena itu, diperlukan kajian perkuatan lereng dengan dinding penahan tanah tipe Counterfort. Kajian ini bertujuan untuk menganalisis stabilitas lereng dengan mendapatkan angka faktor keamanan dan mengidentifikasi pola keruntuhan lereng. Analisis dilakukan untuk mendapatkan faktor keamanan dan pola keruntuhan lereng yaitu dengan menggunakan program Plaxis 2D dan metode irisan. Perhitungan faktor keamanan untuk dinding penahan tanah tipe Counterfort dilakukan secara manual. Adapun parameter  tanah input yang digunakan adalah berat volume kering (gd), berat volume basah (gw), permeabilitas (k), modulus young (Eref), paisson’s rasio (υ), sudut geser (f), kohesi (c). Hasil analisis stabilitas lereng pada kondisi eksisting menggunakan program Plaxis dan metode irisan dengan jari-jari (r) 65,06 meter didapatkan akan faktor keamanan sebesar 1,038 dan 1,079 dengan kondisi lereng tidak aman (FK < 1,25). Hasil analisis setelah diperkuat dinding penahan tanah tipe counterfort dan minipile dengan panjang 12 meter didapatkan angka faktor keamanan 1,268 dengan kondisi lereng tidak aman (FK < 1,5). Dengan demikian, maka diperlukan perkuatan tambahan dengan menggunakan angkur pada counterfort. Hasil analisis stabilitas lereng setelah diperkuat dinding penahan tanah tipe counterfort, minipile dan angkur dengan panjang 20 meter serta sudut kemiringan 30° didapatkan angka faktor keamanan 1,513 dengan kondisi lereng aman (SF > 1,5).Kata kunci : longsoran; counterfort; plaxis 2D; faktor keamanan.


2019 ◽  
Vol 5 (2) ◽  
Author(s):  
A'isyah Salimah ◽  
Muhammad Fathur Rouf Hasan ◽  
Suripto Suripto ◽  
Yelvi Yelvi ◽  
Imam H Sasongko

Permukaan tanah tidak semua berbentuk bidang datar, namun memiliki perbedaan ketinggian dan kemiringan pada setiap daerah. Perbedaan ketinggian tanah mampu mengakitbatkan terjadinya pergerakan tanah yaitu longsor. Keberadaan bangunan base transceiver station (BTS) tower di Desa Sukaresmi, Cisaat, Sukabumi yang berada pada daerah lereng curam dengan kondisi retaining wall dan pagar dalam keadaan retak dan mengalami penurunan tanah menjadi salah satu faktor yang mengancam keselamatan. Untuk mengantisipasi dampak kerusakan lingkungan bertambah parah dibutuhkan penanganan khusus. Penelitian ini bertujuan untuk melakukan analisis stabilitas dan perkuatan lereng menggunakan software Plaxis2D. Adapun metode penelitian dilakukan dengan melakukan investigasi lapangan secara langsung, pengujian laboratorium, analisis stabilitas perkuatan lereng dengan software Plaxis2D serta rekomendasi perbaikan drainase. Upaya perkuatan lereng dengan mengganti dan memperdalam retaining wall existing. Hasil perkuatan lereng dapat meningkatkan nilai safety factor menjadi 1,369, nilai ini lebih besar dari safety factor existing sebesar 1,302. Kata kunci: cisaat, longsor, Plaxis2D, stabilitas lereng. The soil surface is believed to have differences in height and slope in each region. The different elevation could cause land movements namely landslides. The existence of tower base transceiver station (BTS) buildings in Sukaresmi Village, Cisaat,  Sukabumi on a deep slope area with cracked retaining walls and fences condition which experienced settlement is one of the factors that threaten safety. To anticipate the impact of environmental damage getting worse requires special handling. The aim  of this study is to analyze the stability and slope reinforcement using Plaxis2D software. The research method is carried out by conducting direct field investigations, laboratory tests, reinforced slope stability analysis with Plaxis2D software and drainage refinement recommendations. Countermeasures to strengthen the slope are done by replacing and deepening the existing retaining wall. The result of this measure is the increase of the safety factor value to 1,369, this value is greater than the value of the existing safety factor of 1,302. Keywords : cisaat, landslide, Plaxis2D, slope stability.


1998 ◽  
Vol 35 (4) ◽  
pp. 591-599 ◽  
Author(s):  
Zuyu Chen ◽  
Songmei Li

The generalized method of slices, commonly used in slope stability analysis, can be extended to determine active earth pressures applied to various types of supports. The governing force and moment equlibrium equations are given. In a similar manner to slope stability analysis, the methods of optimization are used to define the critical slip surface that is associated with the maximum wall pressure. Examples show that the approaches give active earth pressures identical to the Rankine solution for gravity walls. For other types of support, such as anchored or strutted walls, the earth pressure is determined by assigning appropriate locations of the point of application on the wall. It has been found that applying the restrictions of physical admissibility is more vital in earth pressure problems than in slope stability assessments.Key words: earth pressure, limit equilibrium method, the method of slices, retaining walls.


1985 ◽  
Vol 22 (4) ◽  
pp. 477-482 ◽  
Author(s):  
L. D. Baikie

The use of partial factors of safety in geotechnical design is introduced in the second edition of the Canadian Foundation Engineering Manual. The partial factors have been obtained from comparisons with conventional methods of analysis. Studies presented herein for simple slopes, cantilevered rigid retaining walls, flexible sheet pile walls, shallow strip foundations, and pile foundations indicate that modifications to some of the suggested partial load and resistance modification factors are necessary if comparable designs are to be obtained. Key words: factor of safety, partial factors, limit states design, slope stability, retaining walls, shallow foundations, deep foundations, bearing capacity.


Author(s):  
İnan Keskin

Abstract— The use of natural stones in retaining wall has been a tradition and common practice throughout human history. Stone retaining walls are load bearing retaining walls, which have long been analyzed by considering the equilibrium of forces and moments applied to the wall treated as a rigid solid. Stone retaining walls can be designed for the provision of some slope stability. This paper provides a review of stability analysis of high stone retaining walls. This paper provides a review of stability analysis of high stone retaining walls using Geo5 software. The stone retaining wall examined in this study is located in Karabük (Turkey). The study area was located near of the North Anatolian Fault Line (NAF) which are the most important fault lines in Turkey. For that reason, the stability analyzes were carried out considering the earthquake situation. The stone retaining wall is made of traverten type rock. This rock is a commonly observed rock type. The height of the analyzed wall is 10 m. A 5 kPa uniformly distributed load was adopted in the stability analysis to accommodate for the heaviest loading condition during construction. The analysis with Geo5 found a wall factor of safety 1.78. At this value, it shows that the wall will stable although it is very high.   Index Terms— Stone masonry walls, slope stability, Geo5, Turkey


2020 ◽  
Vol 156 ◽  
pp. 02016
Author(s):  
Deni Irda Mazni

Landslide is one of the potential disasters that can take life and material. A way to reduce disaster risk in slopes is to improve slope stability. A challenge in improving slope stability is how to make soil retaining walls that are simple, quickly built, and workable in the process. This research focuses on laboratory tests of gravity, segmental, and pre-cast retaining walls in sands. The tested models are slopes with different segmental, pre-cast, gravity walls made of un-reinforced concrete for static loads. The slope failure patterns were observed with their load variations. There are two wall models segmental. Each segmental wall observed a collapse pattern that occurred behind the wall. Static loading is carried out step by step until collapse occurs in the segmental wall. Observations and defects are carried out during the load process until the segmental wall collapses. This research shows that segmental pre-cast retaining walls with specific models and sizes can be selected to support certainly given loads to prevent slope failure.


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