Pathological mechanisms of amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis refers to a neurodegenerative disease involving the motor system,the cause of which remains unexplained despite several years of research.Thus,the journey to understanding or treating amyotrophic lateral sclerosis is still a long one.According to current research,amyotrophic lateral sclerosis is likely not due to a single factor but rather to a combination of mechanisms mediated by complex interactions between molecular and genetic pathways.The progression of the disease involves multiple cellular processes and the interaction between different complex mechanisms makes it difficult to identify the causative factors of amyotrophic lateral sclerosis.Here,we review the most common amyotrophic lateral sclerosis-associated pathogenic genes and the pathways involved in amyotrophic lateral sclerosis,as well as summarize currently proposed potential mechanisms responsible for amyotrophic lateral sclerosis disease and their evidence for involvement in amyotrophic lateral sclerosis.In addition,we discuss current emerging strategies for the treatment of amyotrophic lateral sclerosis.Studying the emergence of these new therapies may help to further our understanding of the pathogenic mechanisms of the disease.

Influence of lateral pressure on mechanical behavior of different rock types under biaxial compression

Lots of field investigations have proven that layer-crack structure usually appears during the excavation process of deep rock or coal mass.To provide experimental data for studying the formation mechanism of layer-crack structure,this study researches the influence of lateral pressure on the mechanical behavior of different rock types.Four rock types have been tested and the formation mechanism of macro-fracture surface is analyzed.Results indicate that the brittleness and burst proneness of rock or coal material are stronger than that of gypsum material due to the different mineral compositions and structures.When the lateral pressure is less than 10%uniaxial strength,the peak stress and elastic modulus increase with the increase of lateral pressure;but when the lateral pressure is larger than 10%uniaxial strength,the two parameters decrease slightly or keep steady.This is because when the lateral pressure reaches a certain value,local failure will be formed during the process of applying lateral pressure.Under the condition of low lateral pressure,the failure of the specimen is dominated by the tensile mechanism;under the condition of relatively high lateral pressure,the area of the specimen close to the free surface is tensile splitting failure,and the area far from the free surface is shear failure.

Beyond p-y method:A review of artificial intelligence approaches for predicting lateral capacity of drilled shafts in clayey soils

In 2023,pivotal advancements in artificial intelligence(AI)have significantly experienced.With that in mind,traditional methodologies,notably the p-y approach,have struggled to accurately model the complex,nonlinear soil-structure interactions of laterally loaded large-diameter drilled shafts.This study undertakes a rigorous evaluation of machine learning(ML)and deep learning(DL)techniques,offering a comprehensive review of their application in addressing this geotechnical challenge.A thorough review and comparative analysis have been carried out to investigate various AI models such as artificial neural networks(ANNs),relevance vector machines(RVMs),and least squares support vector machines(LSSVMs).It was found that despite ML approaches outperforming classic methods in predicting the lateral behavior of piles,their‘black box'nature and reliance only on a data-driven approach made their results showcase statistical robustness rather than clear geotechnical insights,a fact underscored by the mathematical equations derived from these studies.Furthermore,the research identified a gap in the availability of drilled shaft datasets,limiting the extendibility of current findings to large-diameter piles.An extensive dataset,compiled from a series of lateral loading tests on free-head drilled shaft with varying properties and geometries,was introduced to bridge this gap.The paper concluded with a direction for future research,proposes the integration of physics-informed neural networks(PINNs),combining data-driven models with fundamental geotechnical principles to improve both the interpretability and predictive accuracy of AI applications in geotechnical engineering,marking a novel contribution to the field.

Exploring mechanism of hidden,steep obliquely inclined bedding landslides using a 3DEC model:A case study of the Shanyang landslide in Shaanxi Province,China

Catastrophic geological disasters frequently occur on slopes with obliquely inclined bedding structures(also referred to as obliquely inclined bedding slopes),where the apparent dip sliding is not readily visible.This phenomenon has become a focal point in landslide research.Yet,there is a lack of studies on the failure modes and mechanisms of hidden,steep obliquely inclined bedding slopes.This study investigated the Shanyang landslide in Shaanxi Province,China.Using field investigations,laboratory tests of geotechnical parameters,and the 3DEC software,this study developed a numerical model of the landslide to analyze the failure process of such slopes.The findings indicate that the Shanyang landslide primarily crept along a weak interlayer under the action of gravity.The landslide,initially following a dip angle with the support of a stable inclined rock mass,shifted direction under the influence of argillization in the weak interlayer,moving towards the apparent dip angle.The slide resistance effect of the karstic dissolution zone was increasingly significant during this process,with lateral friction being the primary resistance force.A reduction in the lateral friction due to karstic dissolution made the apparent dip sliding characteristics of the Shanyang landslide more pronounced.Notably,deformations such as bending and uplift at the slope’s foot suggest that the main slide resistance shifts from lateral friction within the karstic dissolution zone to the slope foot’s resistance force,leading to the eventual buckling failure of the landslide.This study unveils a novel failure mode of apparent dip creep-buckling in the Shanyang landslide,highlighting the critical role of lateral friction from the karstic dissolution zone in its failure mechanism.These insights offer a valuable reference for mitigating risks and preventing disasters related to obliquely inclined bedding landslides.

Recent Advances in 2D Lateral Heterostructures

Recent developments in synthesis and nanofabrication technologies offer the tantalizing prospect of realizing various applications from twodimensional(2D)materials.A revolutionary development is to flexibly construct many different kinds of heterostructures with a diversity of 2D materials.These 2D heterostructures play an important role in semiconductor and condensed matter physics studies and are promising candidates for new device designs in the fields of integrated circuits and quantum sciences.Theoretical and experimental studies have focused on both vertical and lateral 2D heterostructures;the lateral heterostructures are considered to be easier for planner integration and exhibit unique electronic and photoelectronic properties.In this review,we give a summary of the properties of lateral heterostructures with homogeneous junction and heterogeneous junction,where the homogeneous junctions have the same host materials and the heterogeneous junctions are combined with different materials.Afterward,we discuss the applications and experimental synthesis of lateral 2D heterostructures.Moreover,a perspective on lateral 2D heterostructures is given at the end.

Production of AZ80/Al composite rods employing non-equal channel lateral extrusion

In order to simultaneously take the advantages of magnesium and aluminum alloys, AZ80/A1 composite rods were produced using non-equal channel lateral extrusion （NECLE） process at different temperatures. Scanning electron microscope （SEM） and energy dispersive spectrometer （EDS） tests as well as the shear punch test were employed to study the quality and strength of the bond between the two alloys. It was found that the process temperature was an important factor affecting the level of interfacial bonding, such that increasing the temperature from 250 to 300℃ has improved the strength by 37% and the thickness of the bond between the layers by 4.5%. Moreover, this temperature rise reduced the maximum required forming load by 13%. However, the hardness tests showed that this increase in the process temperature resulted in 4% decrease in the hardness of the composite bar.

Future therapeutic implications of new molecular mechanism of colorectal cancer

High incidence(10.2%)and mortality(9.2%)rates led to the ranking of colorectal cancer(CRC)as the second most malignant tumor spectrum worldwide in 2020.Treatment strategies are becoming highly dependent on the molecular characteristics of CRC.The classical theories accept two models depicting the origin of CRC:The progression of adenoma to cancer and transformation from serrated polyps to cancer.However,the molecular mechanism of CRC development is very complex.For instance,CRCs originating from laterally spreading tumors(LST)do not adhere to any of these models and exhibit extremely serious progression and poor outcomes.In this article,we present another possible pathway involved in CRC development,particularly from LST,with important molecular characteristics,which would facilitate the design of a novel strategy for targeted therapy.

Behaviour of Batter Micropiles Subjected to Vertical and Lateral Loading Conditions

Micropiles are drilled and grouted piles having diameter between 100 to 250 mm. Due to its small diameter, it is suitable for low headroom and limited work area conditions. It can be installed without noise nuisance, without vibrations to surrounding soils and structures and without disruption to the production operations in industries which makes micropiles suitable for underpinning and seismic retrofitting of structures. It is necessary to therefore understand the behaviour of micropiles under different loading conditions. This work is on vertical and battered micropiles with different length/diameter ratio (L/D) subjected to vertical and lateral loading conditions. Batter angles had a significant influence on both the vertical and lateral load carrying capacity. The ultimate vertical load was found to increase upto a 30°batter. The ultimate lateral load was found to increase significantly with increasing L/D ratios upto an L/D ratio of 30 for vertical and 48 for battered piles, beyond which the increase was found to be not significant. In general, negative battered micropiles offered more lateral resistance than positive battered micropiles. The results of the study indicated that the ultimate load capacity and mode of failure of the micropiles are a function of the angle of batter, direction of batter and the L/D ratio for vertically and laterally loaded micropiles.

Numerical investigation of the failure mechanism of cubic concrete specimens in SHPB tests

Cylindrical specimens are commonly used in Split Hopkinson pressure bar(SHPB)tests to study the uniaxial dynamic properties of concrete-like materials.In recent years,true tri-axial SHPB equipment has also been developed or is under development to investigate the material dynamic properties under tri-axial impact loads.For such tests,cubic specimens are needed.It is well understood that static material strength obtained from cylinder and cube specimens are different.Conversion factors are obtained and adopted in some guidelines to convert the material streng th obtained from the two types of specimens.Previous uniaxial impact tests have also demonstrated that the failure mode and the strain rate effect of cubic specimens are very different from that of cylindrical ones.However,the mechanical background of these findings is unclear.As an extension of the previous laboratory study,this study performs numerical SHPB tests of cubic and cylindrical concrete specimens subjected to uniaxial impact load with the validated numerical model.The stress states of cubic specimens in relation to its failure mode under different strain rates is analyzed and compared with cylindrical specimens.The detailed analyses of the numerical simulation results show that the lateral inertial confinement of the cylindrical specimen is higher than that of the cubic specimen under the same strain rates.For cubic specimen,the corners aremore severely damaged because of the lower lateral confinement and the occurrence of the tensile radial stress which is not observed in cylindrical specimens.These results explain why the dynamic material strengths obtained from the two types of specimens are different and are strain rate dependent.Based on the simulation results,an empirical formula of conversion factor as a function of strain rate is proposed,which supplements the traditional conversion factor for quasi-static material strength.It can be used for transforming the dynamic compressive strength from cylinders to cubes obtained from impact tests at different strain rates.

Can cannabinoids be a potential therapeutic tool in amyotrophic lateral sclerosis？

Amyotrophic lateral sclerosis（ALS） is the most common degenerative disease of the motor neuron system. Over the last years, a growing interest was aimed to discovery new innovative and safer therapeutic approaches in the ALS treatment. In this context, the bioactive compounds of Cannabis sativa have shown antioxidant, anti-inflammatory and neuroprotective effects in preclinical models of central nervous system disease. However, most of the studies proving the ability of cannabinoids in delay disease progression and prolong survival in ALS were performed in animal model, whereas the few clinical trials that investigated cannabinoids-based medicines were focused only on the alleviation of ALS-related symptoms, not on the control of disease progression. The aim of this report was to provide a short but important overview of evidences that are useful to better characterize the efficacy as well as the molecular pathways modulated by cannabinoids.

Shear failure behaviors and degradation mechanical model of rockmass under true triaxial multi-level loading and unloading shear tests

The redistribution of three-dimensional(3D)geostress during underground tunnel excavation can easily induce to shear failure along rockmass structural plane,potentially resulting in engineering disasters.However,the current understanding of rockmass shear behavior is mainly based on shear tests under2D stress without lateral stress,the shear fracture under 3D stress is unclear,and the relevant 3D shear fracture theory research is deficient.Therefore,this study conducted true triaxial cyclic loading and unloading shear tests on intact and bedded limestone under different normal stress σ_(n) and lateral stressσ_(p)to investigate the shear strength,deformation,and failure characteristics.The results indicate that under differentσ_(n)and σ_(p),the stress–strain hysteresis loop area gradually increases from nearly zero in the pre-peak stage,becomes most significant in the post-peak stage,and then becomes very small in the residual stage as the number of shear test cycles increases.The shear peak strength and failure surface roughness almost linearly increase with the increase inσ_(n),while they first increase and then gradually decrease asσ_(p)increases,with the maximum increases of 12.9%for strength and 15.1%for roughness.The shear residual strength almost linearly increases withσ_(n),but shows no significant change withσ_(p).Based on the acoustic emission characteristic parameters during the test process,the shear fracture process and microscopic failure mechanism were analyzed.As the shear stressτincreases,the acoustic emission activity,main frequency,and amplitude gradually increase,showing a significant rise during the cycle near the peak strength,while remaining almost unchanged in the residual stage.The true triaxial shear fracture process presents tensile-shear mixture failure characteristics dominated by microscopic tensile failure.Based on the test results,a 3D shear strength criterion considering the lateral stress effect was proposed,and the determination methods and evolution of the shear modulus G,cohesion c_(jp),friction angleφ_(jp),and dilation angleψjpduring rockmass shear fracture process were studied.Under differentσ_(n)andσ_(p),G first rapidly decreases and then tends to stabilize;cjp,φ_(jp),andψjpfirst increase rapidly to the maximum value,then decrease slowly,and finally remain basically unchanged.A 3D shear mechanics model considering the effects of lateral stress and shear parameter degradation was further established,and a corresponding numerical calculation program was developed based on3D discrete element software.The proposed model effectively simulates the shear failure evolution process of rockmass under true triaxial shear test,and is further applied to successfully reveal the failure characteristics of surrounding rocks with structural planes under different combinations of tunnel axis and geostress direction.

健脾补肾方对肌萎缩侧索硬化小鼠的干预效果及作用机制

目的探索健脾补肾方对肌萎缩侧索硬化(ALS)模型小鼠运动功能的影响及其机制。方法将12只采取转基因法繁育的保留部分运动功能的ADAR2flox/flox/VAChT-Cre小鼠(AR2小鼠)随机分为模型组和治疗组,每组6只;以6只同批次野生型(WT)小鼠为对照组。治疗组小鼠灌胃给予健脾补肾方[30 g/(kg·d)],对照组和模型组小鼠灌胃给予0.2 mL氯化钠溶液(9 g/L),每日1次,连续干预8周。每周观察小鼠活动状况、体质量以及抓力、抗疲劳能力(滚轮测试)等行为学功能。第24周后取样,采用苏木精-伊红(HE)染色法、尼氏染色法观察各组小鼠脊髓前角组织病理变化,采用Western blot法检测各组小鼠脊髓组织中作用于RNA的腺苷脱氨酶2(ADAR2)、转录反应DNA结合蛋白-43(TDP-43)的蛋白表达量,透射电镜观察小鼠脊髓组织超微结构。结果与对照组比较,模型组小鼠体质量随周龄逐渐增长;与模型组比较,治疗组小鼠体质量降低。与对照组比较,模型组小鼠与治疗组小鼠抗疲劳程度均有所下降,但是治疗组小鼠的抗疲劳能力下降相对模型组有所延缓。与对照组比较,模型组小鼠抓力下降;与模型组比较,治疗组抓力下降相对减缓。与对照组相比,模型组TDP-43表达量显著降低(P<0.001);与模型组相比,治疗组TDP-43表达量显著升高(P<0.05)。与对照组相比,模型组ADAR2表达量显著降低(P<0.01),治疗组与模型组之间ADAR2表达量没有显著差异(P>0.05)。与对照组相比,模型组脊髓前角运动神经元损伤严重,神经元结构不完整;与模型组相比,治疗组神经细胞凋亡数量减少。透射电镜下,模型组与对照组比较出现明显的线粒体肿胀凋亡、髓鞘脱散现象;治疗组与对照组相比较存在部分髓鞘脱散、线粒体肿胀,相对于模型组,存在肿胀凋亡现象的神经细胞数量有所减少。结论健脾补肾方能延缓ALS模型小鼠运动功能的减退,减少脊髓运动神经元的凋亡和损伤,阻止散发性ALS(sALS)病理异常标志物TDP-43的生成,保护脊髓神经元有髓神经纤维与线粒体,有效延缓ALS小鼠疾病的进展与功能的丧失。

有限元仿真分析不同矫形方式治疗青少年特发性脊柱侧凸的生物力学特征

背景:青少年特发性脊柱侧凸不对称的生物力学环境会导致椎体进一步楔形变,严重时或可影响心肺功能,压迫神经。不同侧凸程度的青少年特发性脊柱侧凸应进行运动、支具或手术治疗,然而,因患者的个体差异性,选择不同矫形方式的力学机制仍不明确。目的:基于青少年特发性脊柱侧凸患者的脊柱模型,探究不同矫形方式治疗的生物力学机制,为临床治疗方式的选择提供依据。方法:基于1例青少年特发性脊柱侧凸患儿脊柱CT图像,于Mimics软件中三维重建出脊柱侧凸模型(C7-L5),在T8/T9胸廓处施加横向侧推力,在C7椎体上方施加纵向撑开力,力的大小为20,40,60,80,100,120 N,分析两种矫形方式下椎间盘凹凸侧应力、椎体凹凸侧位移和脊柱Cobb角变化。结果与结论:①横向侧推力下,C7T1-T7T8椎间盘应力无明显变化,T7T8-L4L5节段凹凸侧应力随着侧推力的增加先减小后增大,侧推力对T8T9附近节段的矫正效果明显,随着节段延伸至头端和尾端,矫正效果减弱;侧推120 N时,胸部Cobb角由53.2°变为32.5°,腰部Cobb角由50.2°变为43.9°;②纵向撑开力下,胸椎椎间盘应力先减小后增大,腰椎椎间盘应力均减小,C7位移最明显,节段延伸至尾端,矫正效果逐渐减弱;撑开力120 N时,胸部Cobb角由53.2°变为39.4°,腰部Cobb角由50.2°变为47.6°;③提示两种矫形方式均对脊柱侧凸程度有一定改善,胸部矫正大于腰部矫正,同时凹凸侧不对称的应力分布也得到改善,这有助于骨逐渐恢复正常生长;脊柱侧凸Cobb角较大时,适合采用纵向撑开方式,脊柱侧凸Cobb角较小时,适合采用横向侧推方式;研究结果有助于理解脊柱矫形机制并为矫形方式的选择提供理论依据。

Capacity and failure mechanism of laterally loaded jet-grouting reinforced piles: Field and numerical investigation

This study presents the results of field and numerical investigations of lateral stiffness, capacity, and failure mechanisms for plain piles and reinforced concrete piles in soft clay. A plastic-damage model is used to simulate concrete piles and jet-grouting in the numerical analyses. The field study and numerical investigations show that by applying jet-grouting sur- rounding the upper 7.5D （D = pile diameter） of a pile, lateral stiffness and beating capacity of the pile are increased by about 110% and 100%, respectively. This is partially because the jet-grouting increases the apparent diameter of the pile, so as to en- large the extent of failure wedge and hence passive resistance in front of the reinforced pile. Moreover, the jet-grouting pro- vides a circumferential confinement to the concrete pile, which suppresses development of tensile stress in the pile. Corre- spondingly, tension-induced plastic damage in the concrete pile is reduced, causing less degradation of stiffness and strength of the pile than that of a plain pile. Effectiveness of the circumferential confinement provided by the jet-grouting, however, diminishes once the grouting cracks because of the significant vertical and circumferential tensile stress near its mid-depth. The lateral capacity of the jet-grouting reinforced pile is, therefore, governed by mobilized passive resistance of soil and plastic damage of jet-grouting.

Stability Control of Gob-Side Entry Retaining in Fully Mechanized Caving Face Based on a Compatible Deformation Model

The stability control of gob-side entry retaining in fully mechanized caving face is a typical challenge in many coal mines in China.The rotation and subsidence of the lateral cantilever play a critical role in a coal mine,possibly leading to instability in a coal seam wall or a gob-side wall due to its excessive rotation subsidence.Hence,the presplitting blasting measures in the roof was implemented to cut down the lower main roof and convert it to caved immediate roof strata,which can significantly reduce the rotation space for the lateral cantilever and effectively control its rotation.Firstly,the compatible deformation model was established to investigate the quantitative relationship between the deformation of the coal seam wall and the gob-side wall and the subsidence of the lateral cantilever.Then,the instability judgments for the coal seam wall and gob-side wall were revealed,and the determination method for the optimal roof cutting height were obtained.Furthermore,The Universal Distinct Element Code numerical simulation was adopted to investigate the effect of roof-cutting height on the stability of the retained entry.The numerical simulation results indicated that the deformation of the roadway could be effectively controlled when the roofcutting height reached to 18 m,which verified the theoretical deduction well.Finally,a field application was performed at the No.3307 haulage gateway in the Tangan coal mine,Ltd.,Shanxi Province,China.The field monitoring results showed that the blasting roof cutting method could effectively control the large deformation of surrounding rocks,which provided helpful references for coal mine safety production under similar conditions.

Numerical analysis of soil-rock mixture's meso-mechanics based on biaxial test

Soil-rock mixture(S-RM)is a widely distributed geotechnical medium composed of "soil" and "rock block" different both in size and strength. Internal rock blocks form special and variable meso-structural characteristics of S-RM. The objective of this work was to study the control mechanism of meso-structural characteristics on mechanical properties of S-RM. For S-RM containing randomly generated polygonal rock blocks, a series of biaxial tests based on DEM were conducted. On the basis of research on the effects of rock blocks' breakability and sample lateral boundary type(rigid, flexible) on macroscopic mechanical behavior of S-RM, an expanded Mohr-Coulomb criterion in power function form was proposed to represent the strength envelop. At the mesoscopic level, the variations of meso-structure such as rotation of rock block, and the formation mechanism and evolution process of the shear band during tests were investigated. The results show that for S-RM with a high content of rock block, translation, rotating and breakage of rock blocks have crucial effects on mechanical behavior of S-RM. The formation and location of the shear band inside S-RM sample are also controlled by breakability and arrangement of rock blocks.

The Effect of Lateral Guiding Mechanism on Noise Characteristics in Semiconductor Lasers

A comparison between intensity noise spectra and also the line shapes of gain-guided, weakly-index-guided, and strongly-index-guided semiconductor lasers are made using numerical solution of Maxwell-Bloch equations including spontaneous emission noise.

深部沿空巷道锚固围岩破坏失稳能量驱动机理

深部沿空巷道受侧向顶板断裂所产生的动载影响,锚固围岩易产生大变形,甚至破坏失稳。以山东省孙村煤矿31120工作面上平巷为工程背景,首先采用YTJ20型岩层探测记录仪获得了锚固顶板裂隙发育规律及以脆性张裂破坏为主的破坏方式。然后,通过相似材料模拟试验方法获得了深部沿空巷道侧向顶板前期、过渡期和后期3个运动阶段典型特征,并分析了不同阶段锚固围岩破裂演化及能量释放规律;其中过渡期运动阶段锚固围岩内部应力、变形量急剧增大,裂隙发育明显,能量释放显著,对沿空巷道锚固围岩稳定性影响最大。最后,构建了侧向顶板断裂运动下沿空巷道结构力学模型,给出了锚固围岩输入能量与可抵抗能量定量计算方法,揭示了侧向顶板断裂诱发锚固围岩破坏失稳能量驱动机理,并定义了失稳能量判据,即当作用在沿空巷道锚固围岩上的能量大于锚固围岩可抵抗能量时,将发生破坏失稳。进一步地,提出了锚固围岩失稳风险等级划分方法和相应地控制技术,计算结果表明,31120工作面沿空巷道锚固围岩失稳风险等级为中风险。采取加强支护措施后,沿空巷道顶底板及两帮移近量分别减小35.47%和35.71%,锚索受力减小23.43%,变形速度明显降低,锚固围岩能量积聚程度减小。

侧向搅拌摩擦增材制造工艺优化与力学性能特征分析

为研究侧向搅拌摩擦增材制造工艺参数对增材区材料力学性能的影响,建立了响应面模型,对模型进行了回归分析,基于响应面法对工艺参数进行了优化,并通过方差分析验证了模型的可靠性。结果表明,在增材参数为旋转速度为982.81r·min^(-1),增材速度为36.147mm·min^(-1),下压量为2.428mm时增材区的最大抗拉强度为252.72MPa,断后伸长率为11.82%。根据工艺过程对最优工艺参数进行修正,随后进行5层侧向搅拌摩擦增材制造试验,并进行力学性能特征分析。结果表明,修正后最优工艺参数下增材区拉伸性能与母材性能相当,拉伸试件断裂方式为韧性断裂;后一层增材区硬度高于前一层增材区。

厚硬顶板悬顶致灾机理及切顶控制技术研究

针对侧向厚硬悬顶下临空巷道围岩变形大、失稳风险高的问题,以大同马脊梁煤矿3810工作面运输巷为工程背景,建立了厚硬侧向悬顶力学模型,确定合理切顶位置理论值为内错煤柱3.98 m。建立UDEC数值计算模型,分析了厚硬悬顶长度、断裂位置对煤柱应力分布及3810运输巷围岩变形的控制效果,结果表明:降低悬顶长度、在煤柱上方合理位置断裂,能够有效降低煤柱侧向应力集中程度,减少巷道围岩的破坏范围及变形。根据分析结果,确定煤柱采空区侧厚硬悬顶进行切顶卸压控制,促使厚硬顶板及时垮落,提高采空区顶板垮落带高度,从而降低煤柱承载的载荷并为煤柱提供侧向约束,提高煤柱承载性能。提出了厚硬侧向悬顶水压致裂切顶卸压控制方案并应用于现场,结果表明:3810运输巷采取水力压裂切顶措施后,巷道围岩变形得到显著改善;切顶后巷道两帮最大值移近量为600 mm,顶板最大下沉量为277 mm;相对于未采取切顶方案的区段,巷道变形量分别降低39.6%(两帮)、31.8%(顶板),巷道有效断面能够满足矿井安全高效生产的需要。