On July 7, a delegation of experts including Huo Wenying, Chief Engineer of the China Architecture Design & Research Group; Ma Hong, Hebei Provincial Engineering Survey and Design Master and Chief Engineer of the Hebei Architectural Design & Research Institute; and Chai Weimin, Chief Engineer, successively visited the China Huaneng Headquarters project to observe and provide guidance on the fluidized solidified soil trench backfill works. Li Shengyuan, Deputy Director of the Marketing Center of Zhongyan Dadi, and others extended a warm reception.

As one of the first batch of landmark relocation projects in Xiong'an New Area, the China Huaneng Headquarters Building has, since the day of commencement, shouldered the important mission of establishing a national model project for high-quality development. The project is located in the headquarters business district of the Start-up Area, with a total construction area of approximately 111,100 square meters. The new headquarters building extends across three separate plots; the above-ground portion includes a 26-story tower on the north side with a height of 130 meters, as well as a 9-story tower on the south side and a 4-story podium. Functions include offices, conference rooms, a management center, corporate exhibition, supporting services, and ancillary facilities. Upon completion, the project will accumulate successful experience for the relocation of central enterprise headquarters and is of great significance for further leveraging the clustering and demonstration effect of Xiong'an New Area and accelerating the pace of undertaking relocations.

It was the Minor Heat solar term, with the summer sun blazing, and the China Huaneng Headquarters project site was already dotted with tower cranes, with construction in full swing. The delegation of leaders and experts, with keen interest and accompanied by Zhongyan Dadi's on-site technical personnel, inspected the basic conditions of the project along the route: the trench has a depth of 15 meters and a width of about 1 to 1.5 meters, making it a typical trench project characterized by large backfill depth and narrow backfill space and implementation site. In addition, as the new headquarters of China Huaneng Group, the project fully embodies the characteristics of a world-class clean energy enterprise and innovative design requirements. Through ground-source wells beneath the park foundations, ground-source wells in the park, and air-source systems, it meets the park's winter heating and summer cooling needs, building a green zero-carbon benchmark project. Therefore, numerous ground-source heat pump pipes are embedded and protrude in different areas within the trench.

Based on the above basic project conditions, due to the narrow and deep trench and insufficient working space, traditional backfill methods such as lime soil or graded sand-gravel make it difficult to meet design requirements for compaction and uniformity through rolling, and are prone to significant post-construction settlement and seepage problems, as well as easy damage to the ground-source heat pump pipes. In contrast, the fluidized solidified soil backfill method, cast in place on site, can achieve self-leveling, self-compaction, flexible construction, and water-stop and anti-seepage performance, while meeting the design strength requirements for trench backfill, with high construction efficiency, no cross-operation damage, no dust pollution throughout the process, and no post-construction settlement.

Zhongyan Dadi further explained its technical characteristics to the expert delegation: fluidized solidified soil is produced by adding curing agent and water to on-site excavated surplus soil and waste residue, mixing into a mixture with a certain fluidity for trench backfill, and through casting, curing, and hardening, ultimately forming solidified soil with a certain strength and excellent anti-seepage and waterproof performance for permanent filling of the trench space. Its mechanism is to cement soil particles through inorganic binders and promote curing reactions, thereby enhancing and improving the performance of the hardened soil body, especially increasing strength, water stability, and impermeability. The use of fluidized solidified soil as backfill material mainly offers the following four advantages:

After carefully listening to Zhongyan Dadi's presentation on the various advantages, application scenarios, and construction processes of solidified soil used for trench backfill engineering, the expert delegation highly praised and fully affirmed Zhongyan Dadi's technical research and development strength and the advantages of fluidized solidified soil for trench backfill, and also put forward more valuable suggestions for the upgrading, promotion, and application of this technology.

Zhongyan Dadi has always adhered to the philosophy of "delighting others and achieving oneself, innovating for excellence," devoted itself with great enthusiasm to the construction of Xiong'an New Area, and has always been committed to the research, development, and application of distinctive geotechnical engineering technologies and materials, continuously driving technological innovation in the geotechnical industry. The successful application of fluidized solidified soil trench backfill in the China Huaneng Headquarters project not only demonstrates Zhongyan Dadi's strength in scientific and technological research and development and achievement transformation, but also marks another solid step by Zhongyan Dadi in actively responding to and practicing the concept of green development, supporting the construction of key projects in Xiong'an New Area, and promoting the coordinated development of the Beijing-Tianjin-Hebei region, contributing its modest efforts and corporate responsibility to the millennium project of striving to open up new prospects for advancing the construction of Xiong'an New Area with high standards and high quality.