水坝工程
RCC Dam Construction — Placing, Compaction and Joint Treatment
Lei, the RCC placement for the gravity dam is progressing well. You're placing lifts every 8 to 10 hours and the dam is rising about 2.5 meters per week. Walk me through the quality control on the current lift.
雷工，重力坝RCC浇筑进展顺利。每8到10小时铺一层、坝体每周升高约 2.5米。给我过一遍当前浇筑层的质量控制。
雷工: Each lift is placed at 300 mm loose thickness — after compaction with the 10-ton double-drum vibratory roller, it settles to about 280 mm compacted. We're using a high- paste RCC mix with 120 kg/m³ of cement and 80 kg/m³ of Class F fly ash. The VeBe consistency time is 16 to 20 seconds — provides good workability for the dozer to spread and the roller to compact.
每层松铺300 mm——用10吨双钢轮振动碾压实后约280 mm。用高胶凝料RCC 配比，水泥120 kg/m³ + F级粉煤灰80 kg/m³。VeBe稠度时间16到20秒—— 给推土机摊铺和振动碾压实提供了良好的和易性。
The lift joint between layers — that's where RCC dams can have problems if not handled correctly. What's your procedure?
层间接缝——处理不好RCC坝容易在这里出问题。你们的程序是什么？
雷工: We follow the "hot joint" philosophy whenever possible. The spec requires the next lift to be placed within 400 degree- hours of the previous lift — that's the temperature in Celsius multiplied by the time in hours. At our ambient temperature of 28°C, 400 degree-hours gives us about 14 hours. We're doing 8 to 10-hour cycles, so we're well within the window.
我们尽可能遵循"热缝"原则。指标要求上一层初凝前400℃-h内铺下一层 ——就是摄氏温度乘以小时数。28°C环境温度下400℃-h约等于14小时。我们 8到10小时一循环，远在窗口期内。
Before each new lift, we green-cut the surface with a high- pressure water jet at 25 MPa — that removes the surface laitance and exposes the coarse aggregate. Then we spread a 15 mm thick bedding mortar layer — 1:2 cement-sand mix with a water-reducing admixture — just ahead of the RCC placement. This ensures a monolithic bond between lifts.
每层新浇前，用25 MPa高压水枪冲毛——清除表面浮浆、露出粗骨料。然 后在RCC摊铺前铺15 mm厚接缝砂浆——1:2水泥砂配比加减水剂。确保层间胶 结成一个整体。
RCC工长: The compaction QC on this lift — we're doing nuclear density testing every 500 m². Results: 98.2%, 98.5%, 97.9% of modified Proctor. Spec minimum is 98%. One reading at 97.9% is borderline — we gave that spot two extra roller passes and re-tested: now 98.3%. All passing.
这层的压实QC——每500 m²做核子密度检测。结果：修正普氏98.2%、 98.5%、97.9%。指标最低98%。97.9%那个点在临界线——加碾了两遍重测：现 在98.3%。全部通过。
Curtain Grouting and Dam Safety Monitoring
Lei, the curtain grouting for the dam foundation is about 70% complete. We're now grouting the critical section under the river channel where the rock is more fractured. The Lugeon values from the water pressure tests ranged from 8 to 25 Lu in this zone — that's moderately permeable.
雷工，坝基帷幕灌浆完成约70%。正在河道下关键段灌浆，那里岩石更破碎。 压水试验吕荣值在这个区为8到25 Lu——中等透水性。
雷工: What's your grouting strategy for this high-permeability zone?
对这个高透水区灌浆策略是什么？
We're using three rows of grout holes. The upstream row is inclined 15° upstream to intersect vertical fractures. The middle row is vertical, and the downstream row is inclined 15° downstream. Primary holes are at 12-meter centers, secondary holes split to 6 meters, and where the Lugeon values are still above 5 Lu after secondary grouting, we drill tertiary holes at 3-meter centers.
用三排灌浆孔。上游排向上游倾斜15°以截断垂直裂缝。中间排垂直，下游 排向下游倾斜15°。一序孔中心距12米、二序加密到6米，二序后吕荣值仍高于 5 Lu的地方再打三序孔加密到3米。
浆液配合比从水灰比3:1开始，如果吃浆量大就逐步变浓到1:1和0.5:1。灌浆 压力在基岩面以下5米处为0.5 MPa，逐渐增加到帷幕底部的1.5倍坝高水头。 我们灌了约850吨水泥——比原估算多了15%，但这说明岩石裂隙确实被充分填充 了。
The grout mix starts at a water-cement ratio of 3:1, then we thicken progressively to 1:1 and 0.5:1 if the take is high. Grouting pressure is 0.5 MPa at 5 meters below the rock surface, gradually increasing to 1.5× the dam height in water head at the curtain bottom. We've injected about 850 tons of cement — about 15% above the estimate, but that tells us the rock fractures are being properly filled.
监测工程师: Let me update you on the dam instrumentation readings. The piezometers in the drainage gallery show that the uplift pressure behind the grout curtain is only 18% of the full reservoir head — the design assumed 25%, so we're better than expected. The drainage holes are discharging about 0.8 liters per minute per meter of gallery — very low and stable. No sign of curtain degradation.
我汇报一下大坝监测仪器读数。排水廊道渗压计显示帷幕后的扬压力仅为 全水头的18%——设计假设25%，比预期好。排水孔流量约每米廊道每分钟0.8升 ——很低且稳定。帷幕无退化迹象。
雷工: The pendulum readings — what about the dam deformation?
正倒垂读数——坝体变形怎么样？
监测工程师: The direct pendulum at the crest shows a maximum downstream displacement of 12 mm at full reservoir — the design prediction was 15 mm. The radial displacement follows the expected seasonal pattern: downstream in winter when the reservoir is full, upstream in summer during drawdown. All within normal behavior. No unexpected trends.
坝顶正垂线显示满库时最大向下游位移12 mm——设计预测15 mm。径向位移 遵循预期的季节性规律：冬季满库向下游、夏季降库向上游。全部在正常行为 范围内。没有意外趋势。