充填开采是控制岩层移动并降低地表沉降与环境损害的重要途径，而充填材料来源不足和充填成本高昂现成为制约井工煤矿充填开采推广应用的主要瓶颈。探寻重点区域的低充填率靶向充填新方法与配套技术是充填开采的研究热点之一。为解决上述问题，结合煤矿井下结构充填的学术思想，深入研究了顶板岩层断裂特征，明确了顶板岩层破断块体尺寸及铰接形态，识别了破断铰接块体主沉降区域，判定出结构充填的关键位置。结合关键位置确定方法，提出重点控制基本顶最大挠度位置，即板结构潜在张拉断裂位置(塑性铰发育位置)的“工字型”结构充填新方法。结合新阳矿岩层地质参数，借助FLAC^3D数值模拟软件，深入分析了工作面采宽和推进方向上顶板岩层内应力、竖直沉降、塑性区分布规律，揭示了不同方案下充填体稳定性演变特征。结果表明：“工字型”充填在节省充填用量的基础上，较垮落式开采减少初采期直接顶沉降量33.47%，与全部充填仅相差2.3%。同时，关键位置充填体能有效应对顶板回转下沉引起的应力集中，保持自身稳定性，实现对顶板的长效支撑。综合分析得到了新阳矿首采工作面初采期“工字型”结构充填最佳充填方案为中部条带长度72 m，宽度7 m，两侧条带长度18 m，宽度6 m，较全部充填可减少充填材料成本33.86万元。该方案形成的密闭空间为1 980 m³，占总采出空间的44%，可用来储能或碳封存，助力实现零碳绿色开采，推动双碳目标的实现。

Backfilling mining is important for controlling strata movement and reducing surface subsidence and environmental damage. Insufficient sources of raw materials and high backfilling costs have become major bottlenecks, limiting the application of backfill mining in underground coal mines. Exploring new methods and supporting technologies of targeted backfill with low backfilling rate in key areas is one of the research hotspots in backfilling mining. To solve these problems, combined with the academic thought of constructional backfill in underground coal mines, an in-depth study of the fracture characteristics of roof strata is conducted, the hinged shape and size of broken blocks in the roof strata are clarified, the main subsidence area and position of broken hinged blocks are identified, and the key position of the constructional backfill is determined accordingly. Through the key position determination method, an “I-shaped” constructional backfill new scheme that focuses on controlling the maximum deflection position of the main roof, i.e., the potential tensile fracture position (plastic hinge development position) of the plate structure, is proposed. Combined with the geological parameters of the rock strata of Xinyang Mine, FLAC^3D numerical simulation software was used to analyze the stress, vertical subsidence, plastic zone distribution of the roof in the direction of mining width and advancing direction of the working face, and the stability evolution characteristics of backfilling body under different schemes are revealed. The results show that the “I-shaped” backfill can reduce the immediate roof subsidence in the initial mining period by 33.47% compared with the caving mining on the basis of saving the backfilling amount, and there is only a difference of 2.3% with the full backfill. At the same time, the backfilling body at the key position can effectively response the stress concentration caused by the rotation and subsidence of the roof, maintain its stability, and realize the long-term support for the roof. After comprehensive analysis, the best backfilling scheme for the “I-shaped” constructional backfill in the first coal face of Xinyang Mine is 72 m in length and 7 m in width in the middle strip, and 18 m in length and 6 m in width in the two side strips. Compared with full backfill, the cost of backfilling materials can be reduced by 0.338 6 million yuan. The scheme creates a confined space of 1980 m³, or 44% of the total mining space, which can be used for CO₂ or carbonized material sequestration, helping to achieve zero-carbon green mining and promote dual-carbon goals.