Li Menglong Li

Dr. Li Menglong Li


Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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8 February 2023 in Energies
Verified
Journal Article
Open access
PDF file
YZYongqiang Zhang
Yongqiang Zhang
Xiang-yu WangXiang-yu Wang
Xiang-yu Wang
FZFeiteng Zhang
Feiteng Zhang
LLLi Menglong Li
Li Menglong Li
GWGuanghui Wang
Guanghui Wang
XZXiangqian Zhao
Xiangqian Zhao
On the working face below shallow and close coal seams, there are residual pillars. The mine’s ability to operate safely is constrained by the coal pillars’ vulnerability to sudden instability and powerful ground pressure disasters during withdrawal. This paper uses the 31,106 working face of the Huoluowan coal mine as its research backdrop and employs field observation, theoretical analysis, and numerical simulation to examine the strong dynamic load mechanism of the overlying coal pillars. According to the analysis, the residual pillar’s stress diffusion angle is 29 degrees after mining the working face above it, which has an impact on the main roof’s stability above the working face’s retracement roadway. The main roof is impacted by the excavation disturbance and the remaining pillars during the working face’s final mining phase, displaying a complex stress superposition state. The retracement roadway is significantly deformed as a result of the plastic zone of the surrounding rock changing from small-scale damage to extensive damage. The proposed “hydraulic roof cutting + reinforcement support” prevention technology is based on the prevention idea of weakening important rock strata, changing the stress transmission path, and strengthening adjacent rock. Field testing shows how hydraulic fracturing reinforces the roof structure, lessens the heavy dynamic load on the supporting pillars of overlying residual coal, reduces rock deformation in the retracement roadway, and ensures the stability of the working face during withdrawal. The study’s findings are significant for the secure removal of a working face under similar circumstances.

20 April 2023 in Applied Sciences
Verified
Journal Article
Open access
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GLGuanjun Li
Guanjun Li
Xiang-yu WangXiang-yu Wang
Xiang-yu Wang
JBJianbiao Bai
Jianbiao Bai
YZYongqiang Zhang
Yongqiang Zhang
FZFeiteng Zhang
Feiteng Zhang
LLLi Menglong Li
Li Menglong Li
Roof weighting failures of pre-driven recovery rooms may cause huge economic losses and even casualties. The excessive dynamic load from the sliding of the broken main roof rock block causes the recovery room roof and inner supports to lose their support capacity during the last weighting. Discrete element software UDEC was used to investigate the surrounding rock deformation of the pre-driven recovery room with the main roof break at different positions. The results show that when the recovery room’s length from the main roof rock layer’s fracture region is short, the immediate roof is subjected to high deviatoric stress and the occurrence of horizontal stress concentration due to the deflection of the fractured rocks, and eventually the roof supports fail owing to the development of macroscopic shear crack zones. In this research, the hydraulic fracturing technique was applied to pretreat the main roof (fine-grained sandstone) of the 31108 panel at Huoluowan Coal Mine. Field observations suggest that the strength and duration of the periodic weighting after hydraulic fracturing treatment are both significantly reduced, effectively maintaining the bearing layer performance of the roof of the recovery room and coal pillar walls. The proposed fracturing design offers an effective method of ground control to the coal mines facing roof weighting failures of recovery rooms.

30 July 2026 in Applied Sciences
Verified
Journal Article
Open access
PDF file
XZXiangqian Zhao
Xiangqian Zhao
QLQingtao Liu
Qingtao Liu
JBJianbiao Bai
Jianbiao Bai
XMXinjie Ma
Xinjie Ma
YGYun-bo Gou
Yun-bo Gou
XLXudong Liu
Xudong Liu
The dynamic load generated by the fracture of a hard roof significantly disturbed the stability of the surrounding rock in the lower roadway of the study site. This study established a dynamic transmission model of hydraulic fracture mesh and analyzed the influence of the hydraulic fracture mesh parameter on dynamic load attenuation from the perspectives of energy distribution and stress wave attenuation. The SHPB numerical model was established and calibrated based on PFC2D, and the findings were as follows: the hydraulic fracture mesh changes the rock into a discontinuous structure, which hinders the propagation of dynamic load and changes the medium of dynamic load propagation, resulting in part of the dynamic load being reflected and accumulating in the mesh area, causing the rock in the mesh area to break up or making the rock on the side of the hydraulic mesh to slip, which reduces the energy of the dynamic load. Finally, an industrial experiment was conducted on the 10107 working face of Huayuan Coal Mine. Monitoring results showed that the deformation of the roadway sides and roof was reduced by 833 mm and 861 mm, respectively, and the stability of the surrounding rocks of the roadway was effectively improved.

25 June 2026 in Applied Sciences
Verified
Journal Article
Open access
PDF file
LLLi Menglong Li
Li Menglong Li
Xiang-yu WangXiang-yu Wang
Xiang-yu Wang
QWQingwei Wang
Qingwei Wang
JBJianbiao Bai
Jianbiao Bai
GWGuanghui Wang
Guanghui Wang
FZFeiteng Zhang
Feiteng Zhang
To address severe stress concentration, excessive convergence, and instability of the roadside backfill body (RBB) in gob-side entry retaining (GER) under thick and hard roof conditions, this study investigates the control mechanism of main roof fracture position on surrounding rock stability, using the 3−101 working face of Huoluowan Coal Mine as a case study. A combined approach integrating theoretical analysis, numerical simulation, and field investigation is adopted. A statically indeterminate mechanical model based on masonry beam theory is established to characterize the lateral roof fracture behavior. The deflection and bending moment distributions are derived, and a criterion for fracture position determination is developed based on the maximum bending moment condition. The theoretical results indicate that the natural fracture position is located approximately 9.4–11.2 m inside the gob boundary. Numerical simulations using UDEC Trigon under different fracture positions (−2 m, 1 m, 5 m, and 9 m) show that fracture location significantly affects the mechanical response of GER. Fractures occurring above the roadway or RBB induce large deformation levels and more extensive plastic zones, while gob-side fracture conditions correspond to relatively lower disturbance levels and improved structural stability. The RBB exhibits shear-dominated failure characteristics, and the displacement distribution is non-uniform along height, with larger deformation in the middle-to-upper region. To improve stability, a coordinated control strategy combining anchor cable reinforcement and directional long-distance hydraulic fracturing (HF) is proposed to regulate the main roof fracture position through the formation of artificial weak planes. Field monitoring results show that the maximum displacements of the roof, floor, and ribs are 558 mm, 233.5 mm, and 71.3 mm, respectively, with a convergence ratio of 19.8%. Borehole imaging confirms the development of hydraulic fractures within the designed roof stratum, supporting the effectiveness of the proposed control approach. These results demonstrate that the fracture position of the main roof plays a key role in controlling GER stability, and its regulation provides an effective means for improving roadway performance under complex geological conditions.