【正文】 Creek Dam, the aggregate was produced from an andesitebasalt(安山玄武巖) outcrop（露頭） about 3000 ft (910 m) upstream and to the right of the dam. Rock was hauled to the primary jaw crusher, located in the quarry(采石場), using 85ton {77metricton} end dump trucks（后卸式卡車）. Rock was crushed to 9in (230mm) maximum sizes. The aggregate was transported from the quarry down a 12 percent slope by a 56inwide, 2085ftlong ( x 635 m) conveyor belt rated at 1000 tons/h (907t/h) and stored in a surge pile using a radial stacker(棧式料倉). A series of cone crushers and screens then produced 3in (75mm), 1in (38(mm), and 3/4in (19mm) aggregate sizes. The aggregate was transferred from these stockpiles by three 7yd3 ( m3) frontend loaders into movable hoppers discharging onto five conveyors which fed the batch plant surge piles. From there, the material was loaded from reclaim tunnels onto 36inwide (910mm) conveyor belts and transported to the RCC and conventional concrete batch plant aggregate bins(貯料倉). The Elk Creek layout is shown in Fig. 。 and a revolution counter（旋轉(zhuǎn)式稱量臺） for metering cement through the ital display was available for realtime measurement of aggregate feed. For aggregate, cement, and water, the system provided cumulative data every 5 min. Transporting RCC Transport of RCC can be by scraper(鏟土機) conveyor, bottomand reardump trucks, large frontend loaders or a bination of these. Continuous, highspeed conveyors appear to be the most desirable method for large RCC jobs. Scrapers have worked well on most mediumsize projects, and rear dumps have been used successfully on a variety of jobs. Segregation(分離) of the larger aggregate, usually occurs with end dumps, and attention must be directed to this potential problem.Spreading and leveling can be done with a spreader box, bull dozer, frontend loader, scraper, or end dump. Wheeled equipment is generally inferior to tracked (有軌的)equipment, which generally moves productionrate jobs.A contractorbuilt spreader box mounted on a large shovel（推土機）frame was used with limited success to place, 210,000 Yd3 (161,000 m3) of RCC at Galesvil1e Dam. Dump trucks were used to fill the 16yd3 (12m3) spreader box. The box could place RCC in lanes from 13 to 19 ft wide (4 to m) and to unpacted depths of between 15 and 17 in(38 to 43 mm).Smoothtired 16yd3 (12 m3) rock trucks modified with jobdesigned airactuated（氣動的）spreader boxes attached to the tailgate were used successfully at Upper Stillwater to dump and spread RCC into 18in (460mm) layers. Fine grading was done with a lasercontrolled D4 dozer. The end dumps were filed on the dam by a conveyor system.End dumps have been used exclusively in Japan for transporting RCC. Segregation problems have been addressed to some extent in the mix design. What segregation does occur is rectified by hand labor and the Japanese method of dumping RCC in piles and spreading several layers of the material with dozers before pacting the layers into a thick lift.Whatever transport method is used, the intent should be to get the material in place quickly, as close to its final location in the lift as possible and with little rehandling or exposure to weather. If haul vehicles are used, bottomdump trailer trucks or largecapacity, wheeled tractorscrapers offer best results. Because of the higher unit weight of RCC, weight rather than the volumetric capacity of the vehicle will probably control the amount of material hauled per trip. If batch mixing is used, matching of the capacity of the haul unit to the batch mixers is critical.Bottom dumps, because of their short discharge drop distance, minimize segregation. Scrapers force the mix out of the bowl and place it in a relatively uniform layer that requires little secondary spreading. Scrapers have good maneuverability, top load well, and the bowl unloads with few problems. But their basic design is for digging and rough hauling. Consequently, a scraper with the same horsepower as a truck will not haul material as efficiently. Scrapers are more mobile than bottomdump trailer trucks in difficult terrain, however, and have better distribution of stress under the tires.Haul roads need to be laid out, constructed, and maintained to limit damage from turning and to prevent contamination of the RCC lift surface from mud, old RCC, or cement spillage and any other foreign material. Tire cleaning may be required as vehicles approach the dam. In many cases, access roads near the dam need to be surfaced to prevent tracking of the material onto the lift. The use of clean, crushed rock for the haul roads at Galesville Dam kept the tires of the haul fleet clean.At Monksville Dam, the designers originally specified that RCC hauled to the dam from surge hoppers near the dam or entirely by conveyor belt to avoid tracking of contaminants onto the dam. Instead, the contractor was allowed to use scrapers to haul RCC from the batch plant to the point of placement provided that: All vehicles entered or left the dam surface in a straight line via a lane parallel to the axis and immediately adjacent to the downstream slope. Contaminated haul roads were cleaned immediately by a fulltime crew working exclusively on cleanup. The contractor repaired all damaged RCC at the entry and exit points by removing and replacing it. All travel on the dam was in one direction without any turns.Because of the extra vigilance(警惕性), the difficulty of getting RCC repair work done quickly, and the incautious operation of equipment, project engineering were dissatisfied with the method used for hauling RCC at Monksville. Hauling RCC from the mixing plant to the dam can cause other plications. Raising the access road to keep up with the daily increase in the height of the dam bees a cost and scheduling consideration. Also, for most RCC dams, gaining access from the upstream side can be difficult because of space and scheduling conflicts with work being done on the