柔模砼墙沿空留巷工作面覆岩垮落结构与砼墙的稳定性是留巷成功与否的关键。以大柳塔煤矿52606工作面为研究对象，通过相似材料模拟实验发现在52605工作面和52606工作面回采结束后，砼墙上方覆岩垮落呈短悬臂梁结构，且砼墙侧垮落角均大于煤壁侧垮落角，二次采动后2个工作面裂隙贯通向地表发育，砼墙上方地面出现略微沉降。针对上述情况，通过分析覆岩垮落结构特征，确定了沿空巷道顶板第1次断裂位置位于采空区上方充填体一侧，第2次断裂位置位于采空区形成悬臂梁结构的岩层中靠近煤壁侧，并结合理论分析得到柔模砼墙沿空留巷应力分布特征。根据沿空巷道不同使用阶段门式支架是否撤出，提出留巷阶段砼墙的支护阻力采用分离岩块法计算，巷道复用阶段砼墙的支护阻力采用倾斜岩梁法计算；柔模砼墙的稳定性与安全系数有关，工作面回采过程中保证安全系数大于1，则砼墙不会发生失稳破坏。实例验证结果表明：该留巷工作面使用门式支架做临时支护时，为保证砼墙的安全系数大于2，需保证砼墙强度达到5.4 MPa以上；撤出门式支架后，断裂岩块及其覆岩载荷由砼墙承担，且采动引起的动载不断对砼墙产生影响，但砼墙的安全系数为3.9，砼墙仍相对稳定；砼墙应力虽然是不断变化的，但变化幅度都不大，均未出现应力急剧增大或减小的现象，这说明砼墙可有效支撑顶板，且砼墙一直处于稳定状态。

The stability of the gob-side entry retaining with flexible concrete walls and the collapse structure of the overburden above the working face are key factors that determine the success of entry retaining. Taking the 52606 working face at Daliuta Coal Mine as the research object, a similar material simulation experiment was conducted. The results showed that after mining the 52605 and 52606 working faces, the overburden above the concrete wall collapsed into a short cantilever beam structure. The side collapse angle of the concrete wall was greater than that of the coal wall. After secondary mining, fractures developed from the two working faces, connecting to the surface, and slight ground subsidence appeared above the concrete wall. Based on the analysis of the overburden collapse structure characteristics, it was determined that the first fracture of the roof in the gob-side entry occurred on the side of the backfill material above the gob area, while the second fracture occurred in the rock layer forming the cantilever beam structure near the coal wall. Combining theoretical analysis, the stress distribution characteristics of the flexible concrete walls in the gob-side entry were obtained. According to whether the portal support was removed during different stages of gob-side entry usage, it was proposed that the support resistance of the concrete wall during the retaining phase should be calculated using the separated rock block method, while the support resistance during the reuse phase should be calculated using the inclined rock beam method. The stability of the flexible concrete wall was found to be related to its safety factor. During the mining process, as long as the safety factor remained greater than 1, the concrete wall would not experience instability or failure. Verification results showed that when portal support was used as temporary support during the retaining phase, to ensure the safety factor of the concrete wall was greater than 2, its strength had to exceed 5.4 MPa. After the portal support was removed, the fractured rock blocks and overburden load were borne by the concrete wall. Additionally, dynamic loads caused by mining continued to affect the concrete wall. However, the safety factor of the concrete wall was 3.9, indicating that the wall remained relatively stable. Although the stress on the concrete wall changed continuously, the changes were not significant, and no sharp increases or decreases in stress were observed. This suggests that the concrete wall could effectively support the roof, maintaining stability throughout.