Collaborative bearing mechanism of support body-accumulation body along gob for gob-side retention gateway
XIN Yajun
TIAN Menghan
JI Hongying
ZHANG Dongying
GAO Zhongguo
REN Jinwu
ZHAO Kang
Abstract：Gob-side retention gateway is widely used to improve coal mining rate and to achieve Y ventilation in working face and mining-driving balance,and the support body inside gateway fails easily in lateral pushing action of the falling gangue in the gob.Based on the instability a-nalysis of support body subjected to the lateral force in gob-side retention gateway,the concept of gob-side filling accumulation body along the gob in gateway was proposed,the stability model of the gob-side support body-accumulation body in retention gateway was established,the influencing factors of support body-accumulation body stability were analyzed,the charac-teristics of accumulation body strength under different parameters were discussed,the me-chanical tests of the accumulation body were carried out,and the industrial test of support body-accumulation body collaborative bearing was carried out along gob in gob-side retention gateway.The results show that the lateral instability of the support body is the inducing point of the surrounding rock instability in gob-side retention gateway,and the instability of the sup-port body inside gob-side retention gateway mainly manifests as the whole movement instabili-ty and the bending deformation instability.The instability of the support body along the gob inside retention gateway are closely related to the magnitude,direction and position of the lat-eral force generated by the gob caving gangue.The accumulation body with certain strength a-long the gob in the retention gateway is conducive to the stability of the support body.The width and the height of the accumulation body inside gob-side retention gateway are 1 433.3 and 1 708.1 mm respectively(1.5 and 1.7 m for safety consideration)by theoretical model cal-culation,and the actual tensile strength of the accumulation body is 0.121 3 MPa(no less than 0.15 MPa on site).In the same gangue particle-size grading,the relationship between cement content and the strength of accumulation body is nearly linear,and the strength increases slowly as the cement content more than 10％,and the overall peak strain increases firstly and then decreases.In the same cement content,the strength of the accumulation body increases firstly and then decreases with the increase of the gangue particle-size grading,and the strength is achieved the largest in the gangue particle-size grading less than 8 mm,and the o-verall peak strain shows the trend of increase-decrease-increase.The accumulation body P8C10 with particle-size grading less than 8 mm and cement content 10％is the optimal one.After a-dopting the surrounding rock control scheme of support body-accumulation body,the roof sink is not obvious,the average lateral deformation of the support body is controlled within 25 mm,and the surrounding rock of the retention gateway is stable.
Keywords：gob-side retention gatewaylateral instabilitysupport body-accumulation bodycollaborative mechanics modelparameter determinationstability
Publication Date：2025-05-30
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：14( 595-608 )