Construction Of Retaining Walls Research Articles

Modification of Reinforced Concrete Retaining Wall at Pilangbango Reservoir Construction Project Madiun, East Java

The reservoir is the tendon of water in order to accommodate the excess rain water in the rainy season and its utilization in the dry season for various purposes, both in the field of agriculture as well as the interests of the community. To find out the cause of the crack wall of the reservoir Pilangbango Madiun, East Java, then do the test strongly press on concrete walls and soil investigations on the area of the reservoir. Spunpile 400 mm in diameter used by the mounting distance 200 cm and a depth of 12 m and pole mounted on the heels of concrete walls. Manual calculation of the results and analysis of the Finite Element program it can be concluded that in the presence of an additional retaining her 400 spunpile mm using a distance 200 cm and a depth of 12 m, retaining wall construction is then quite able to hold style pillow case and Sliding with style has a safety factor more than 1.5. So the movement of the sliding walls do not happen again.

현장시험과 수치해석을 통한 수평지반반력계수 산정에 관한 연구

흙막이 현장에서 안정성 및 경제적 시공이 이루어지기 위해서는 굴착단계별 토질특성을 반영한 정량적인 정수들이 실제 현장과 일치되어야 한다. 그중 흙막이 설계 시 가장 중요한 매개 변수인 변형계수 및 수평지반반력계수는 현장여건에 따라 표준관입시험의 N값으로 산출하는 것이 일반화되어 있다. 따라서 본 연구에서는 기존의 일반화된 흙막이 설계법의 모순을 극복하고, 실제 현장에 부합하는 수평지반반력계수 산정을 위하여 표준관입시험, 평판재하시험 및 공내재하시험을 실시하고 상호관계성을 비교 분석하였다. 또한, 현장의 실제 계측데이터를 통한 유한요소해석법과 탄소성해석법의 역해석을 통하여 수평지반반력계수와 굴착에 따른 저감계수를 추정하였으며, 궁극적으로 중 소형 및 일반현장에서도 흙막이 벽체 설계 시 합리적인 설계적용을 위한 정수의 오류를 줄이고자 한다. For achieving stability and economic construction at a retaining wall construction site, quantitative parameters of soil properties with excavation steps coincides with the actual field site. The main parameters of retaining wall design such as deformation modulus and modulus of horizontal subgrade reaction are common with N value of standard penetration test. Therefore, this study is compared and analyzed about the mutual relationship which is SPT, PBT and PMT for overcoming inconsistency of the existing retaining wall design generalized. In addition, modulus of horizontal subgrade reaction and reduction factor with excavation steps are proposed through back analysis of elasto-plasticity and finite element method with actual field monitoring data. Finally, it is purpose that parameter errors are reduced for applying effective retaining wall design at a construction small and medium-sized.

Emergency Retaining Wall Replacement: The East 26th Street Slide Repair in Baltimore, MD

During a record rainfall on April 30, 2014, a century-old, stone retaining wall between a dense urban roadway (26th Street) and the CSXT railroad track in Baltimore, MD, failed. The stone retaining wall was approximately 320 ft long and over 40 ft tall. The wall connects two tunnel portals — the railroad tunnel below North Charles Street on the west side, and the railroad tunnel below St. Paul Street on the east side. The failure sent part of the roadway, along with tons of soil, boulders, light poles, and eight packed cars, nearly 40 ft down, obstructing the tracks and halting rail traffic on this very busy railway that provides service between the Port of Baltimore and the north. Fortunately, no one was injured. Video of the failure, captured by onlookers, was broadcast via national media. The failure forced the evacuation of 19 homes until the first phase of earth-retention construction was completed. Due to the time sensitivity of the temporary retaining wall construction, the City of Baltimore (City) engineer, general contractor, and geotechnical contractor collaborated and worked seven days per week until the residents were able to return to their homes.

Application of Prefabricated Retaining Walls with Steel Lagging

It has been known that the conventional retaining wall system with timber lagging and H pile has several problems such as the irregular gap between H-piles, cutting or adding to standard timber, back fill over first step excavation, and especially break-down accident at the disjoint of wall system. In the practical excavation, these problems may lead to workers accident and the inefficiency of construction economy. To solve the above problems, a new method using prefabricated retaining wall was proposed and verified. The characteristics of the new method is to replace timber wall as free-sliding steel-lagging and connector. To check its verification and application, laboratory tests such as bending strength, tensile strength, and fatigue strength were carried out. Also, a pilot test in the field and numerical simulations under various ground conditions were performed. From the researches, it is found that the prefabricated retaining wall plate can be superior to the conventional timber lagging plate in the strength. It is also found that the proposed methods can be effective in the reuse of retaining wall plate and safe in the disjoint of wall system. Finally, it is desired that the proposed method will be effective in the reduction of the imported timbers and helpful in the safety of retaining wall construction.

Laboratory Tests on Failure of Retaining Walls Caused by Sinusoidal Load

The failure of retaining wall construction can be occurred due to the forces acting on the rear wall exceed the capacity of its stability. Dynamic acceleration parameters can affect the movement pattern of granular soil behind the retaining wall. This research aims to study the movement of grain behind the retaining wall by laboratory testing. The retaining wall model was made in the glass box of a length of 2 meters, width of 0.4 meter and height of 1 meter. This models used gravity types, which was made of concrete and was placed on dry sand with a trapezoid-shaped a height of 20 centimeters, width of peak 2 centimeters and width of below 10 centimeters. The model was examined using dry sand material with grain size that can pass through sieve No. 4 and retained on sieve No.100 of loose sand density (γd = 1.4184 gr/cm3). The model was vibrated using shaking tables with a given variation on sinusoidal loads and was recorded using accellerometer. The displacement of granular soil in a particular point was also monitored during vibration. The results shows that there is different grain movements resulted from different acceleration. The increase in vibration accelerates the grain to fill the empty space between the grains. This causes wider movement area of the grain and expands the landslide areas.

The Shape of Slide Surface of Gravity Retaining Walls Construction on Sand by Small Scale Sinusoidal Dynamic Load Tests

The shape of slide surface of retaining wall construction with the gravity-type on soil layer of sand with a sinusoidal dynamic loading is influenced by several dynamic parameters, including: (1) the frequency of vibration, (2) the density of sand soil, (3) deviation and (4) the dynamic acceleration. This research aims to explore the role of dynamic parameters to shape of landslide of retaining wall construction due to dynamic load sinusoidal by small-scale testing in the laboratory. The retaining wall was modeled in the glass box of 2 meters in length, 0.4 meter in width and 1 meter in height. This models used gravity types retaing wall which was made of concrete and was placed on dry sand. The model was examined using dry sand material of loose sand density (ρd = 1.4184 gr/cm3), medium sand density (ρd = 1.5816 gr/cm3) and dense sand density (ρd = 1.6784 gr/cm3). The model was vibrated using shaking tables with a given variation on sinusoidal loads and was recorded using accelerometer. The displacement of granular soil in a particular point was also monitored during vibration. The results show that there is the difference in the maximum vibration acceleration response generated due to differences in the frequency of vibration. The differences in deviation lead to differences of shape of slipe surface areas. The density of sand also affects the width of the slip surface.

Environmental impacts caused by phosphate mining and ecological restoration: a case history in Kunming, China

This paper presents the environmental impacts caused by surface mining and the ecological rehabilitation of Haikou phosphate deposits, Kunming, China. Surface mining entails the removal of the overburden to expose bare rock surfaces, not only causing destruction of pre-existing vegetation, but also occupying large areas of land for dumping the spoil. Severe environmental impacts are caused, e.g. rock desertification, poor forest stand structure, loss of biodiversity, aesthetic depreciation of the landscape, and the potential hazard of landslide and ground erosion. Ecological restoration has been conducted in a demonstration area since 1989 by means of control of geological hazards and revegetation of the disturbed areas. On-site dumping of waste rock for restoration of the abandoned mine area was adopted, providing a new mode of mining reclamation with high economic, environmental, and social value. Countermeasures for prevention and control of landslides included cut and fill technology, drainage, safety netting protection, retaining wall construction, and vegetation cover. By recruiting native plant species to the mine site and planting a forest imitating a natural mixed forest, the mine area was successfully revegetated.

흙막이 가시설의 거동 분석을 통한 안정성 확보 방안에 관한 연구

최근 해석프로그램과 시공기술의 발달에도 불구하고 많은 흙막이 가시설 공사현장에서 구조물의 붕괴로 인한 경제적 인적피해가 발생하고 있다. 이번 연구 현장의 지반조사 결과는 원래 설계시 조사결과와 다른 것으로 나타났다. 이러한 경우에 지반조사 결과를 통해 산정된 매개변수는 오류가 있을 가능성이 있고, 그 지반정수를 활용하여 분석한 가시설 구조물의 거동분석도 비합리적임을 추정할 수 있다. 이번 연구에서는 가시설 구조물에 영향을 주는 매개변수에 대한 상관성을 탄소성해석법을 이용하여 분석하였다. 분석방법으로 탄소성해석법에 적용되는 주요 매개변수(점착력, 지반반력계수, 하중조건)를 변화시키고 그 변화로 인한 흙막이 가시설 재료(부재)의 거동을 분석하였다. 그 결과 점착력이 재료의 거동에 가장 큰 영향을 주는 것으로 나타났다. 따라서 흙막이 가시설의 설계에서 지반조사 결과와 실제 지반의 확인과 여러 매개 변수중에서 점착력의 정확하고 합리적인 산정이 매우 중요함을 알 수 있었다. Recently despite the development of analysis program and construction technologies, collapse at the many earth retaining wall construction site of the structure due to the economic and human damage has occurred. The results of geothechnical investigation studies field, it was found to differ from the results of the original design. There may be errors parameters calculated from the results of ground investigation in such a case. And it can be estimated that it is irrational to behavior analysis of the earth retaining wall were analyzed by utilizing the parameters. And in this study, parameters that affect the earth retaining wall the correlations were analyzed using elasto-plastic method. Analysis method was changed various parameters (cohesion, subgrade reaction coefficient, load condition) applied to the elasto-plastic method. And due to a change in the behavior of earth retaining wall materials were analyzed. As a result, the cohesion greatly affects the behavior of earth retaining wall materials in various parameters. For this reason, the results of the geothechnical investigation, confirmation of the actual ground is very important in the design of the earth retaining wall. And, calculating accurate and reasonable of the cohesion of the various parameters is very important.

BIM기반 고속도로 공사 물량산출 신뢰성 검토 및 활용

In case of applying the BIM method in the civil engineering of irregularly shaped structure, BIM method began to be introduced in the current building engineering area compared with the expected effects of the relatively high construction productivity has been recognized. In this paper, I have developed quantity calculation algorithms applying it to earthwork and bridge construction, tunnel construction, retaining wall construction, culvert construction and implemented BIM based 3D-BIM Modeling quantity calculation. Structure work in which errors occurred in range between -6.28% ~ 5.17%. Especially, understanding of the problem and improvement of the existing 2D-CAD based of quantity calculation through rock type quantity calculation error in range of -14.36% ~ 13.07% of earthwork quantity calculation. It's benefit and applicability of BIM method in civil engineering. In addition, routine method for quantity of earthwork has the same error tolerance negligible for that of structure work. But, rock type's quantity calculated as the error appears significantly to the reliability of 2D-based volume calculation shows that the problem could be. Through the estimating quantity of earthwork based 3D-BIM, proposed method has better reliability than routine method. BIM, as well as the design, construction, maintenance levels of information when you consider the benefits of integration, the introduction of BIM design in civil engineering and the possibility of applying for the effectiveness was confirmed. In addition, as the beginning phase of information integration, quantity document automation program has been developed for activation of BIM. And automatically enter the program code number, linkage and manual volume calculation program, quantity document automation programs, such as the development is now underway, and step-by-step procedures and methods are presented.

Applying building information modelling in environmental impact assessment for urban deep excavation projects

Purpose Due to the rapid development of cities, underground structures, such as deep excavations and tunnels have been widely used to increase underground space. Since these underground structures are often adopted in old and crowded town area, accidents may easily do serious damage to adjacent structure and even cause some casualties. Professional engineering knowledge and experience can reduce or avoid this chain of events. But it is undeniably the case that in more complex urban engineering environments, risks are higher. Construction project teams must therefore consider a wide variety of information when managing risks and making project decisions. Urban deep excavation construction might cause unfavourable effects on the ground and to nearby structures. Environmental impacts need to be evaluated and monitored during the deep excavation construction. Generally, construction project teams will set up monitoring instruments to control and monitor overall environmental status, especially when retaining wall construction, retaining wall excavation, and during groundwater pumping. Voluminous monitoring data and project information are usually created along the delivery processes of construction. It is difficult to view and manage them comprehensively. Method Our research employs the concept of building information modelling (BIM) in environmental impact assessment for urban deep excavation projects. BIM is a relatively new technology that facilitates better information integration and management. Many engineering companies employ BIM for information integration, visualization, and parametric design, to reduce both the duplication of work and the complexity of interface integration. In this research, a 3D-building model, an excavation model, environmental conditions, the results of ground surface settlement analysis, and measurement and monitoring data, were integrated into our system to assist construction project teams to execute environmental impact assessment accurately. The risks and issues affecting safety of excavation and nearby structures might be recognized earlier through conveying information visually in this system. Construction project teams can then handle them immediately. The implementation of the system was carried out in the MicroStation Visual Basic for Applications (MVBA) environment. The Bentley MicroStation supports visualization of the 3D-model and provides some capabilities for 3D-object manipulation and information query. Results & Discussion This system can provide construction project teams a full view of the ongoing project, along with functions to integrate and display information multidimensionally. We will demonstrate the functionalities we developed and verify its feasibility in the O6-underground station of the Kaohsiung metro system.

合成土留壁構造道路トンネルの施工実績

本工事は開削トンネル工事であり，土留壁（SMW）には周辺の住宅地・工場等重要施設への影響を抑えるために剛性の大きい芯材を用いている。この芯材は応力的には余裕があるため，本体側壁の引張部材として有効利用する合成土留壁構造が採用されている。しかしながら，合成土留壁の側壁コンクリート厚は函体高さ約10mに対し0.45mと非常に薄く，施工時の充てん不足やひび割れの発生が懸念される。本報告では，合成土留壁構造構築におけるコンクリート躯体の品質向上に対する現場の取組みについて報告する。

Prediction of rebar profile in a earth retaining RCC structure using cover meter survey

Reinforced concrete retaining walls are generally used for the construction of underground structures, such as coal handling systems, underground subways and railway stations. In some exceptional cases, the retaining walls are used as structural walls for supporting other structures besides retaining the earth. The retaining wall construction is a highly specialized job requiring multidisciplinary activities. One of the major problems is to make a good quality construction ensuring good integral concrete and adequate cover thickness to the rebar cage. In many projects, construction deficiency in the form of exposure of reinforcement and lack of cover occurred at the excavated face of a retaining wall, which posed a challenging problem of determining the actual available cover thickness at the soil face. This problem was addressed by carrying out cover thickness survey and concrete surface profile at the excavated face, based on which a prediction can be made on the rebar cage profile and the available cover thickness at the soil face. This approach and methodology are highlighted in this paper.

Study of Block-formed Retaining Wall for Reducing Construction Waste

Existing retaining walls are usually made from only one cast form and any damage must be promptly repaired. However, when a part of a retaining wall is repaired, a gap can be created between the repaired and existing parts, along with an unpleasing visual effect. As such, the whole structure is often reconstructed, rather than repairing one part, resulting in construction waste and possible contamination of the environment. Accordingly, the current study proposes a construction method for a retaining wall that uses separate blocks to downsize of quantity of construction waste. In addition, by changing the color or modifying the block cover a more environmentally friendly retaining wall construction method is achieved.

ジオテキスタイルを用いた垂直補強土壁の施工事例

ジオテキスタイルを用いた垂直補強土壁の施工事例

Geotextile reinforced brick faced retaining walls

This paper describes a new method of retaining wall construction that combines the reinforced earth technique with a conventional brick wall. Although this type of construction is based on the original reinforced earth construction concept it has some important modifications as it uses short geotextile sheets as reinforcement and has a rigid face. The behaviour of geotextile reinforced brick faced retaining walls was investigated using model walls which were built, backfilled and then surcharged. The results show that even short lengths of reinforcement can significantly increase the load capacity of a brick retaining wall. A visible front lace crack at about mid-height develops during surcharging prior to collapse which always occurs far less quickly than on unreinforced walls, taking several seconds.

A Test Construction of Vertical Retaining Wall Reinforced with Geogrid

The authors carried out a large scale of test embankment where a vertical retaining wall of concrete blocks was used and the backfill was reinforced with geogrid. The height of retaining wall is 5m. This paper reports the results of monitoring the lateral displacements of the retaining wall, strains produced on the geogrid, and so on.Without any trouble, 40 days have passed since the embankment was completed. At the present stage, the lateral displacement of retaining wall measured is about 10cm (including the displacement during construction) at the very outside and the strain on geogrid is about 1%. These results show that our construction method proposed can be successfully applied to actual structures.

Ground movements and deflections of an anchored sheet pile wall in granular soil

Abstract For road construction and improvement schemes in urban areas, the restricted space available has led to an increase in the use of earth retaining structures. The effect of ground movements caused by the retaining wall construction, on adjacent roads, buildings and buried services, is frequently a prime concern in design. The complexity of the construction sequence and the effect of soil-structure interaction generally precludes accurate predictions of ground movement, although an assessment of their upper and lower bounds can be obtained from previous field measurements. This paper describes the pattern of ground movements and deflections of an anchored sheet pile wall forming part of the temporary works for the A1(M) Improvement Scheme at Hatfield, Hertfordshire. This scheme involved the construction of an 1150 m long cut and cover tunnel together with a 350 m length of retained cutting for the tunnel approach. The ground conditions over the tunnel depth consisted of glaciofluvial sands and gravels (Westmill Upper Gravel) overlying a lodgement till deposit (Ware Till). Approximately 2 km of anchored sheet pile walls were used on the scheme to retain the ground during construction of the permanent works. A section of the temporary sheet pile wall was extensively instrumented and observations made both during its construction and over the ten month period when the wall was in service. Measurements of ground movement and wall deflection formed part of a wider research study at the site designed to investigate the behaviour of the sheet pile wall and of the prestressed ground anchors.

Performance of epoxy-coated reinforced earth strips

The laboratory pull-out test results of epoxy-coated and galvanised ribbed reinforcing strips are reported and compared. The results have been used to predict the developed tensile stresses within the reinforcing strips of recent reinforced earth retaining wall construction using a numerical finite element method of analysis. Comparisons with field measurements have also been made.

Construction of a reinforced earth abutment and wall at Maryhill : Smith, R J H Ground Engng, V15, N6, Sept 1982, P33–38

The article reviews the construction of the first UK bridge abutment and associated retaining wall structure to use galvanised ribbed strip for earth reinforcement. The project, carried out in the Maryhill district of Glasgow, which involved the construction of a shopping centre and car park area, required extensive perimeter retaining walls sited on shale/sandstone as well as on made ground, constructed by cost-saving reinforced earth techniques. Details are given of site layout and retaining wall construction techniques for the walls designed to current French practice using ribbed strip soil reinforcement and concrete facing panels. A coefficient of friction of the strip-soil interface used in the design was 1.0 associated with a minimum factor of safety of 2. Casting techniques for the fabrication of the concrete wall facing panels are also described. (TRRL)

Retaining Wall Made of PC Piles with Special Cross-Section

Recently a demand for adopting a noiseless and vibrationless construction method in the field work is growing more and more in Japan.PW-method (or the pile wall construction method) presented in this paper is an unique noiseless and vibrationless construction technique of continuous retaining wall in the field by using precast prestressed concrete piles having special cross-section.Since 1967, when this method was first applied to shore protection works at the Neyagawa River by the Bureau of Construction of Osaka Prefecture, it becomes popular year by year.This paper introduces the outline of “Draft of design code of self-supporting prestressed concrete sheet piles” prepared by the Research Group on “Pre-fabrication of bank-revetment works” in the Society of Materials Science, Japan.Various advantages of PW-method over the retaining wall construction method with temporary horizontal sufforts as well as further improvements needed for PW-method are also discussed. In addition, a convenient method of determining the embedded length of piles is proposed on the basis of the theoretical and experimental results.