The rocks present at the bridge site are heavily jointed. Rock slope protection fabric installation shall conform to section 72, slope protection of caltrans standard specifications except as amended herein. F90tl03 third edition internet october 2000 prepared in cooperation with the us department of transportation federal highway administration. Chapter 18 soil bioengineering for upland slope protection.
For rsp classes i thru viii, use class 8 rspfabric which has lower weight per unit area and it also has lower toughness tensile x elongation, both at break than class 10 rspfabric. January 7, 2019 2 rock bolt and rock dowel construction. Assessing slope protection methods for weak rock slopes in. Practitioners guide and field evaluation of riprap methods racin james a on. Iron spider slope stabilization mesh factory slope. Angular shaped rock may be used on any planned slope. Rock slope design guide page 11 section 100 rock slope design background 101 introduction this manual is intended to provide guidance for the design of rock cut slopes, rockfall catchment, and rockfall controls. Asuccessful rock slope stabilization program requires the integration of a number of interrelated activities, including geotechnical engineering as well as environmental and safety issues, construction methods and costs, and contracting procedures.
Failures of weak rock slopes adjacent to roadsides in southwestern taiwan most often occurred during or immediately after heavy rainfall. Draft rock slope protection general this section includes general specifications for construction rock slope protection. Unlike traditional methods, cc generates no rebound, reduces the need for line or lane possession and can be installed around sensitive infrastructure. Costeffective and sustainable road slope stabilization. Girard spokane research laboratory, national institute for occupational safety and health, spokane, wa. Toe protection methods two methods to provide protection. The design of too flat of a highwall angle means considerable additional mining costs. Methods for analysis of slope stability are described and are illustrated by examples in the appendixes. This practical handbook, together with a companion book, water bioengineering techniques, shows how soils, plants and their ecology can be used to protect and stabilise natural and formed slopes along transportation routes and locations adjacent to industrial, housing areas and leisure facilities. There are field evaluations of sixtyfive sites tabled by location and design method. July 2012 california stormwater bmp handbook 5 of 5.
All natural slopes are subject to continuous erosion forces. Suitable slope protection rip rap materials demonstrate test results that consistently meet these standards. The slope is steep and the toe is close to the highway or railway, there will be no space to excavate a catch ditch or construct a barrier. Rspfabric type of geotextile and quality requirements per section 96 rock slope protection fabric of the standard specifications. Customary units except where a referenced document uses the. On rock slopes, where loss of rock fragments from the face is the prime concern, our macro. There are three material gra requirements based on required rock layer dation thicknesses. An introduction to slope stability and protection j. Design guidelines for wire meshcable net slope protection. This method also involves rigid slope surface protection such as shotcrete, masonry and stone pitching. Hattamleh department of civil and environmental engineering washington state university pullman, washington 991642910 thomas c. Pdf stability analysis of a rock slope in himalayas. This engineer manual em provides guidance for analyzing the static stability of slopes of earth and rock fill dams, slopes of other types of embankments, excavated slopes, and natural slopes in soil and soft rock.
Biotechnical slope protection and earth support donald h. Spider rock protection system for rock slope stabilization. Types of slope protection solid mechanics mechanical. This broad definition encompasses many and varied applications. Chapter 18 soil bioengineering for upland slope protection and erosion reduction part 650 engineering field handbook 182 210efh, october 1992 d applications the soil bioengineering techniques in this document are generally appropriate for immediate protection of slopes against surface erosion, shallow mass wasting. Concrete canvas is increasingly being used as an alternative to sprayed concrete solutions to protect slopes, embankments and cuttings from surface erosion. The method of drilling selected by the specialty contractor will depend on the site and ground conditions and owned drill equipment. California bank and shore cabs rock slope protection design methodology replaced by hec no 23 guidance. On civil projects, rock cuts must be safe from rock falls and largescale slope instability during both construction and operation.
For all other rock sizes within a class, the percentage. California dot does not follow aashto m 288 for their geotextile specifications. California bank and shore rock slope protection design practitioners guide and field evaluations of riprap methods final report no. Rock slope design guide ohio department of transportation. Rock slope engineering civil engineering i am menglim.
Evaluating techniques for monitoring rock falls and slope. United states army corps of engineers engineering manual. For method a placement and the class of rsp described, comply with the rock grading shown in the following table. Paul guyer is a registered mechanical engineer, civil engineer, fire protection engineer and architect with over 35 years experience in the design of buildings and related infrastructure. Evaluating techniques for monitoring rock falls and slope stability edward l. These approaches should not be considered long term permanent. Practitioners guide and field evaluation of riprap methods. Ground anchors or other tie back system may be used together with the retaining structures if the driving forces are too large to resist. Chapter 5 rock slope stabilization 57 scaling a slope at one time. Must be placed to the level of original ground or finished grade shown if you excavate outside the designated pay limits, material placed in those excavation areas must comply. Spider rock protection system for rock slope stabilization joseph c. A third method of rock catchment design is the computer program colorado rockfall simulation program, which simulates rocks tumbling down a slope, predicts the statistical distribution of speed and bounce height, and can be used for locating and designing rockfall mitigation.
Riprap slope protection riprap slope protection is an erosion control measure consisting of geotextile fabric and stone riprap that is placed on an unvegetated slope to protect the soil from erosive forces. Section 1 general sections are reserved in the standard specifications for correlation of special provisions and revised standard specifications with the standard specifications and for future expansion of the standard specifications the specifications are expressed in u. This combined approach is termed biotechnical slope protection. Lowell washington state department of transportation p. Resist degradation and have a durability of 52 minimum caltrans consistency. Construct butress support this is a concrete or masonry gravity structure to retain the rock mass. You may enter part of the word or the whole phrase. Us 225nwe environmental nonwoven geotextile us fabrics. The toe of the riprap should be keyed into a stable foundation at its base as shown in figure 5b. The construction manual contains policies and procedures related to the duties of caltrans division of construction personnel, is for information only, and is intended as a resource for personnel engaged in contract administration. Shotcrete is applying mortar on a slope surface by a certain thickness. Materials rock rock grading shall comply with the following grading table. Slope protection consists of rock, concrete, or concreted rock or slope paving rock slope protection rock should demonstrate stability. Temporary slope protection method for shallow or surficial failures the following are general guidelines for minimizing additional movement of shallow or surficial slope failures during the winter months.
The changes in the design procedure are those that remove references to allowable velocity procedures and replace them with tractive stress evaluations. Statefurnished materials and expenses, as well as supplemental work items and descriptions. The method for placing rock will either be method a or method b, whichever the contract designates, as discussed under section 47203a, rock slope protection, earlier in this section. Design guidelines for wire meshcable net slope protection balasingam muhunthan shanzhi shu navaratnarajah sasiharan omar a. Army corps of engineers cecweg washington, dc 20314 manual no. Rock grading table rock size percentage larger than1 class 1 ton light 2 ton 0 5 1 ton 50 100.
Rock slope stability analysis a variety of engineering activities require excavation of rock cuts. Be alert for new or revised specifications that may affect the current manual guidance for contract administration. Rock slope protection rsp is among various bank and shore protection materials and methods. The design thickness of the riprap should extend a minimum of 3 feet horizontally from the slope. Where rock removal operations are carried out above active highways or railroads, or in urban areas, proper care must be taken to prevent injury or damage from falling of rock.
Hand scaling is effective on small areas that are accessible by workers and that have rocks that are not too big to be removed manually. Hard rock masses with joints, shears, or bedding representing major discontinuities and dipping downslope are excavated along the dip of the discontinuity, although all material should be removed until the original slope is intercepted. Protection apply to the standard bid item 721022 rock slope protection it, method b. Rock slope stability and the design of the appropriate slope angle is extremely important for surface mining in these difficult economic times. You may enter part of the word or the whole phrase all items. Geotechnical approaches for slope stabilization in.
The caltrans office of hydraulics and stormwater design is the sponsor for water pollution control and temporary construction site bmp special provisions. This invention relates to a slope protection method for planting, and more particularly to a method of construction of a plant bed, which not only mechanically stabilizes a slope such as a cut slope or talus that has been left as it is without any means of treatment in the past, but also allows easy growth of plants. Listed below are us fabrics geotextile products that meet the california dot geotextile specification, listed by their application. The rock bolt and rock dowel plan shall include the following. However, selection ofappropriate erosion control protection is difficult because design methods are not well developed. The second was a thorough study of common physical test methods that were believed to have potential for evaluating the quality of rock slope protection material.
Usually one method of retaining wall is not enough and you should combine 23 techniques to achieve the desired result. Some individuals feel rock riprap has been over used in the tahoe basin, depleting. Wrapping of the slope face is always recommended when the slope angle exceeds 34 degrees. Recommended dimensions for flumes are defined as follows. The report clarifies the procedure of the california bank and shore cabs layered rock slope protection rsp design method. Modem methods for design and stabilization of rock slopes were developed in the 1970s. Click on the to search for an item in the contract cost database using the most recent year of data. Advantages, limitations, design guidelines, aesthetic value, construction materials, case examples, relative costs, and maintenance procedures are included for each method. For an additional 9 years he was a principal advisor to. Caltrans identifies eleven different sizes and two placement methods. Protect geomembranes on dams, landfills, and containment basins with the industrys only complete geocell solution featuring the tendon and. Implementation of rock slope protection rsp design following an audit by fhwa, the caltrans bank and shore protection committee formally adopted new rsp guidelines with a modified version ofhydraulic engineering circular hec 23 gradations.
New rsp guidelines are available in chapter 870 and chapter 880 new chapter of. California bank and shore rock slope protection design. Rsp, also called rock riprap or riprap, consists of one or more layers of rock. There are solved problems, figures, and tables for practitioners who design and build flexible rock revetments by the cabs method. The virginia department oftransportation vdot, through the virginia transportation research council vtrc, requested that virginia tech investigate erosion protection for soil slopes along virginiashighways. Protection against scour at the discharge end of the open flume shall be provided in the form of an energy dissipater or other measures such as an saf, rock riprap revetment, or plunge pool. This has been superseded by caltrans new riprap classes.
United states army corps of engineers engineering manual em 111021601. Flat or needle shaped rock must not be used unless the individual rock thickness is greater than 0. Failures and remediation of rock slope stability problems and. Rspfabric type of geotextile and quality requirements per section 96 rock slope. Slope face stabilization for critical slope surfaces state of california. Be careful not to dislodge the underlying base or filter when placing the stones. Protection and treatment to rock slope scaling manual method of removing loose rocks and boulders from exposed rock surfaces. Whether the slope has been recently formed as part of new development, or is in its original natural state, some form of erosion protection may be required. Symbol parameter dimensions f factor of safety against sliding along sheet joint calculated h height of the overall slope or of each bench 60 m or 20 m respectively. Rock grading and quality requirements per standard specifications.
Costeffective and sustainable road slope stabilization and erosion control presents information on costeffective and sustainable road slope stabilization techniques, with a focus on shallow or nearsurface slope stabilization and related erosion control methods used on lowvolume roads. With the steepening of the slope face, the erosion potential of the slope increases due to an over steepened condition that poses difficulty when compacting the slope face material. When footing concrete or masonry is placed on rock, the rock must be fully uncovered and the surface removed to sound rock. Rocks placed over fabric shall be installed in accordance with caltrans method a unless the project plans allow for method b and the conditions in paragraph cs 705. The document was revised to add background information, examples, and a glossary and to expand the bibliography. The authors and local practicing engineers in design. The first consisted of an extensive field evaluation of rock slope protection installations throughout the state. We offer a range of erosion protection solutions to suit. The aesthetics of common rock slope construction and mitigation practices can be enhanced with some modifications. Trbs national cooperative highway research program nchrp synthesis 430. Field survey of weak rock slopes along the national south2 freeway conducted in this study showed that the slope protection methods employed in the study areas mainly included vegetation 82. Geotropism in vetiver 20 a photo essay of vetiver grass applied to various slope stabilization applications by paul truong, tvni technical director. Iron spider slope stabilization mesh factory is specializing in making and supplying spider slope stabilization system,tecco slope stabilization system, slope stabilization steel rope mesh,rockfall drapes and netting,gabion basket,stone box,flexible cable. Recommendations presented in this manual are based on research presented in shakoor.
The caltrans specification contains errors and contradictions, so please read the many notes below the product chart. Stability analysis of a rock slope in himalayas 3 fig. The slope face is vertical with a height h, the failure plane is oriented at an angle. In open pit mining, where slope heights can be many hundreds of meters, the economics of the operation are closely related to the steepest stable slope angle that can be mined. Slope protection maccaferri philippines maccaferri. Asce method based on isbash equation with a modification to account for channel bank slope uses isbash because it is in line with experience to rock size that will resist movement by flow velocity taken 10 feet from bank angle of attack less than 30 degrees s 6w 50 d. Increase in height wont increase the capability of retaining wall, rather it would decrease it. Deep slope erosion control and embankment stabilization. Reinforced soil slopes and embankments for the purposes of this document, a reinforced slope is defined as a compacted fill embankment that incorporates the use of horizontally placed geosynthetic reinforcement to enhance the stability of the soil structure. In civil engineering, projects include transportation systems such as highways and railways, dams for power production and water supply, and industrial and urban development. Where feasible, rock slope protection should avoided where it may be considered unattractive or poses a public safety hazard.
Enter the item description of the code you wish to search for. Angular shapes may be used on any planed slope durability. Rock must be leveled or cut to steps and then roughened. Us 225nwe is a 8 oz marv weight, nonwoven, needlepunched geotextile made of 100% polypropylene staple filaments used for liner protection in landfills. Standard contract items and descriptions for caltrans projects. The integrated techniques such as graphical method, modeling, and simulation were utilized to assess rock slope failures and rockfalls by using. Select rock so that shapes provide a stable structure for the required section. Nov 01, 2001 a major revision of the comprehensive textreference written by worldleading geotechnical engineers who share almost 100 years of combined experience, slope stability and stabilization, second edition assembles the background information, theory, analytical methods, design and construction approaches, and practical examples necessary to carry out a complete slope stability project. Must be soil free of organic matter, trash, or other unsatisfactory material 3. Functions of slope surface protection and earth retaining wall slope protection structures slope protection structures help to stablise the slope and can last a lifetime in protecting surrounding properties from damage and people from injury if they are maintained in a good and functional condition at all times.
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