Embankment Dams: Embankment construction, Part 10 |
Other editions - View all
Common terms and phrases
Atterberg limits blasting borrow areas borrow material borrow pit compacted fill compaction equipment compaction test compactors Construction Control construction staff construction surface contractor cutoff trench density and optimum density and water design standard desired dewatering system direct methods Disk Plow disking ditches drain drainage drilling and blasting Earth Manual EMBANKMENT DAMS embankment zones ensure field density test fill material fill placement filter material fines front-end loaders gravel grout hand compaction hand-operated hauling heavy equipment in-place inspector layer lift thickness loading loose lift maximum density maximum dry density minimum number of passes obtained operations optimum water content oversize rock particles percent pervious fill pervious material Piezometers pipe power tampers processing record samples relative density Ridgway Dam riprap rock fill rockfill dams rubber-tired roller sand screen seepage semipervious Soil Cement spalls specifications stockpile test fill test quarries trucks unsound rocks usually vibration vibratory roller Waddell Dam Weather wellpoint yd³
Popular passages
Page 14 - In-Service training may vary from a few days to several months, depending on the availability of personnel and the complexity of the material to be learned.
Page 22 - As a general rule, the coyote method should be prohibited when quarrying for rockfill structures. In quarry experimentation, the material broken by the first blast should be cleared away not only to determine if the correct gradation has been achieved, but to examine the excavation rock face and the condition of the excavation floor. The power shovel has already been mentioned as the best means of loading blasted rock in quantity, but it must be operated from a relatively level floor. In a normal...
Page 48 - ... with subsequent portions constructed during following years. Where foundations are soft, the embankment may be constructed to a specified elevation and further fill placement deferred for a year or more to permit dissipation of foundation pore pressures or to achieve an adequate degree of consolidation. In a narrow steep valley with rock foundations, the entire embankment may have to be completed to a stipulated elevation by a certain date to prevent overtopping during flood season.
Page 33 - The volume of water required to fill the ring with plastic liner in place is determined, the water and liner removed, and then the hole is dug without moving the ring. The liner is then placed in the hole, and the volume of water required to fill the hole to the top of the ring is determined. The difference between the two volume measurements is the in-place volume of excavated fill material. Apparatus and procedures for large volume water displacement tests are described in the Earth Manual, Vol.
Page 38 - Until inspectors and contractor personnel have gained a "feel" for the amount of water needed, rough computations of the number of gallons to add for a given area should be made, and water applied accordingly. After a few trials, a feel for the proper amount will develop. The coarser and less plastic the soil, the more easily water can be added and worked uniformly into it. It is very difficult to obtain uniform moisture distribution in plastic clays containing lumps, without a "curing" period of...
Page 35 - Methods of Relating Fill Density and Water Content to Maximum Density and Optimum Water Content. - The fill density and water content must be related to laboratory values of maximum density and optimum water content of the same material in terms of percent compaction and variation of fill water content from optimum. For this comparison to be meaningful, valid laboratory values must be selected. Performance of the standard five-point compaction test on...
Page 6 - Sumps and Ditches. - When an excavation such as a cutoff trench is extended to rock or to an impervious stratum, there will usually be some water seeping into the excavation and/or "wet spots" in the bottom of the excavation, even with deep wells or wellpoint systems in operation. Water seeping into the excavation from the upstream and downstream slopes of a long cutoff trench can usually be...
Page 53 - ... fertilizing, seeding or sprigging, compacting, watering, and maintaining as required to establish the turf. Temporary or permanent protection should be established on completed portions of the embankment as soon as possible. The usual practice of waiting until near the end of construction and trimming slopes by filling erosion channels with loose material and then fertilizing and seeding has resulted in continuing maintenance problems at several projects.
Page 29 - For a specific soil containing a known percentage of fines, there exists a specific maximum density to which the soil can be compacted by a given amount of energy; but in order to obtain this maximum density, it is necessary for the soil to be at a specific water content.
Page 26 - A comparison of before and after gradation curves will indicate the probable amount of particle breakage to be expected during handling and compaction. Lift thicknesses must be measured. In-place density of the compacted material after rolling must be determined directly by large-scale conventional methods or indirectly by observing settlement of the fill. The latter method is generally used because conventional density tests in rock fills are difficult and settlement measurements provide a better...