## Appendix A Case Study Project 1: Lengshuibe Auxiliary CSGRD Project  
The Lengshui River Reservoir, located in Mugou Town, Shuicheng County, Guizhou Province, is part of the Wu River system in the Yangtze River Basin. It has a catchment area of 36.5 km\({}^{2}\) (11.8 km\({}^{2}\) clear flow, 9.8 km\({}^{2}\) subsurface flow, 14.9 km\({}^{2}\) depression) and a main river channel 7.54 km long with an average gradient of 61.5%. The reservoir's annual average inflow is 17.62 million m\({}^{3}\), with a rate of 0.559 m\({}^{3}\)/s. Its normal water level is 1767 m, holding 8.52 million m\({}^{3}\), and the dead water level is 1737 m, with a dead storage of 1.2 million m\({}^{3}\). The check flood level is 1769.6 m, and the total storage is 9.56 million m\({}^{3}\). It is a small (Type 1) project, Grade IV. The reservoir supplies 9.31 million m\({}^{3}\) of water to five towns, 720,000 m\({}^{3}\) for irrigation (80% assurance), and releases 1.84 million m\({}^{3}\) for the environment, irrigating 1,764,000 m\({}^{2}\) of farmland (312,667 m\({}^{2}\) of paddy fields and 1,451,333 m\({}^{2}\) of dry land). The auxiliary dam, as shown in Figure 11, 60 m inside the reservoir from the saddle point, is 115 m long with an azimuth of N3.307\({}^{\circ}\)E, a crest at 1771.5 m, a maximum height of 39.5 m, and a width of 6 m. The upstream slope is 1:0.3, and the downstream slope is 1:0.75. Three dam types were considered: clay core wall, concrete-faced rockfill and cemented sand, gravel, and rock (CSGR). The CSGRD, chosen for its moderate cost, ease of construction, and environmental benefits, was built using C\({}_{180}\)6 for the body of the dam and Rich-Mix (C\({}_{180}\)20) for seepage control and cushion layers. CSGR with a volume of about 40,000 m\({}^{3}\) was used for body construction. Construction started in August 2022 and finished in December 2022. * **Case Study Project 2: Shaping I Hydropower CSGRD Project** Located on the mainstream of the Dadu River in Jinkouhe District, Leshan City, Sichuan Province, this concrete and CSGR mixed dam has a maximum height of 63 m, a dam crest elevation of 581.00 m, and a total dam crest length of 327 m. It is the world's first large-scale hydropower project to use CSGRD for its main structure. The total volume of cemented sand, gravel, and rock is approximately 650,000 m\({}^{3}\). The application of cemented materials dam technology (CMD) demonstrates advantages in economy, speed, safety, and environmental protection. The project has achieved a record of filling 100,000 m\({}^{3}\) per month using two sets of mixing equipment. The total storage capacity of the power station is 21.23 million m\({}^{3}\), with a normal water storage level of 577.00 m and a corresponding storage capacity of 18.67 million m\({}^{3}\). The regulating storage capacity is 4.91 million m\({}^{3}\), allowing for daily regulation. The power station has a total installed capacity of 360 MW and operates jointly with Shuangjiangkou and Pugou to guarantee an output of 119 MW and a multi-year average power generation of 1.635 billion kWh. The power supply is provided to the Sichuan Power Grid. C\({}_{180}\)20 CSGR material shall be used to construct cushion layers, protection, and seepage control layers within some sections of the body of the dam. The project began in 2023 and is currently under construction, as shown in Figure 12.  
* **Governing Equations for Paste and Alpha Margins** \[\alpha=P_{tr}-FA_{sv}\times(\frac{FA_{vp}}{FA_{sv}})\] (1)where \(\alpha\) is the paste margin; \(P_{tv}\) is the total paste volume per unit of volume; \(FA_{sv}\) is the total volume of fine aggregate per unit of volume; \(FA_{sv}\) is the total void volume of the fine aggregate per unit of volume; and the ratio \(\frac{FA_{sv}}{FA_{sv}}\) is the void ratio of the fine aggregate.