液压支架四连杆机构的三维建模和运动仿真

液压支架四连杆机构的三维建模和运动仿真
摘要:利用UG的建模模块(model)对液压支架四连杆机构进行快速整体建模,然后应用UG
的运动仿真模块(animation)对支架升架、降架的运动过程进行模拟分析,同时利用标记点对顶梁端
点的运动轨迹进行跟踪,来验证端点最大水平变动量是否满足设计要求。

关键词:液压支架;四连杆机构;三维建模;运动仿真
0引言
三维建模彻底改变了传统设计理念,使设计者头脑中产生的三维实体图形可以直接仿真到屏幕上,既形象又直观。

使设计人员从想象各种视图的困境中解放出来,对于复杂的模型更可避免传统设计方式难以避免的错误。

而在建造物理样机之前,通过建立的三维数字化模型进行运动仿真可以对运动特性及干涉情况进行检验,从而预知设计的机构是否满足要求。

本文以ZTA6500型液压支架为例,应用UG软件探索一种三维整体简化、快速建模和运动仿真的方法。

1UG软件简介
Unigraphics(简称UG)是美UGS公司的拳头产品。

该软件不仅具有强大的实体模型、曲面造型、虚拟装配和产生工程图等设计功能,而且在设计过程中可以进行有限元分析、机构运动分析、动力学分析和仿真模拟,从而提高设计的可靠性。

同时可用建立的三维模型直接生成数控代码,用于产品的加工,其后处理程序支持多种类型数控机床。

另外它所提供的二次开发语言UG/open GRIP,UG/open API简单易学,实现功能多,便于用户开发专用CAD系统。

2液压支架及其四连杆机构液压支架的主要功能是支撑工作面顶板,阻止顶板冒落的岩石窜入作业空间,以保证工作面内机器和人员的安全生产。

由于其工作性质所致,较为关心的是端面距的尺寸,而梁端摆动幅度会对端面距的尺寸造成直接影响。

液压支架四连杆机构的设
计是掩护式和支撑掩护式液压支架整体设计的核心和基础,四连杆机构是由顶梁,掩护梁,前、后连杆和底座五大构件组成。

四连杆机构的主要作用是保证支架的纵向和横向稳定性,承受和传递外载,并能够实现移架,设计的好坏决定着顶梁端点的运动轨迹。

顶梁端点运动轨迹成双纽线形,其最大的水平偏摆量应小于或等于70 mm,最好为30 mm以下。

3液压支架四连杆机构三维实体建模出于理论研究和快速建模的目的,本文将不采
用实际的液压支架模型,而是采用其简化的整体建模形式,其简化原则如下:
顶梁,前、后连杆,掩护梁和底座分别进行整体建模,而不是由许多小零部件组装成的装配体。

实际的液压支架四连杆机构应该是由钢板焊接成的箱
体结构,而本文在创建三维模型时为了快速成型都建成了实体结构。

但四连杆机构各杆长度严格按照图纸的尺寸进行三维建模,其中一些对运动仿真没有直接影响的小部件进行了简化处理,例如:肋板,侧护板等。

在UG的建模(modeling)模块中分别建立顶梁,前、后连杆,掩护梁,立柱和底座整体简化模型,在完成三维模型后,进入装配(assembly)模块完成液压支架整体的虚拟装配。

以ZTA6500型液压支架为例整体建模如图1所示
4液压支架四连杆机构运动仿真液压支架的主要运动形式表现为升架和降架。

本文在对升、降架进行运动仿真的同时,通过在顶梁端点处设置标志点,对顶梁的运动轨迹进行跟踪,跟踪点的坐标值以电子图表的形式输出。

经过处理后,绘制成顶梁端点的运动轨迹图。

运动仿真(Animation)是基于时间的一种运动形式。

即在指定的时间段中运动。

UG的仿真分析依赖于ADAMS解算器,仿真过程分3个阶段进行:前处理(创建连杆、运动副和定义运动驱动);求解(生成内部数据文件);后处理(分析处理数据,并转化成动画、MPEG电影文件、图表
和报表文件)。

(1)创建连杆、运动副和定义运动驱动进入UG/motion模块,创建新的运动分析方案(newScenario)。

在此方案中创建四连杆机构的各构件为连杆(links),其中底座设置为整个系统的机架,即为与地固定连杆。

前、后连杆和底座与顶梁的连接处都设置为旋转副(Revolute Joint),4根立柱和液压缸之间的连接设置成滑动副(Slider Joint)。

液压支架运动的驱动力是
来自液压缸处的伸缩力,本运动方案中运动驱动设定为加载在立柱上的矢量力(Vector Force)。

(2)设置标记和跟踪选择工具栏上标记图标(makers),在顶梁的端点处设置标记点。

然后选择封装选项(packing op-tions)中的跟踪(trace)功能,通过跟踪选项对话框中的分类选择(class selection)设置标记点为跟踪点。

(3)运动仿真
在分析工具条中选择运动仿真图标(Animation)即启动运动仿真过程,在分析选项对话框(AnalysisOptions)中选择机构运动学/机构动力学选项,设时间为5 s,步数为500步,单击OK
启动ADAMS解算器进程,分析完成后,运动仿真对话框自动弹出,此时其中的跟踪(Trace)选项为可选项,可以选择全程方式(full Range)来进行运动仿真,即可以观看升、降架的运动过程。

可以把运动仿真的过程制成MPEG电影文件。

标记点的跟踪坐标可以直接以电子图表来表示。

输出的数值经处理后,绘制成图表如图2所示。

由图2可见顶梁端点的运动轨迹的最大水平摆动量在小于70 mm范围内变化。

符合液压支架四连杆机构设计要求。

5结语
(1)以ZTA6500型液压支架为例介绍了支架整体建模的原则和方法,为液压支架快速建模提供了一种思路。

通过设置标记点,对顶梁的端点运动轨迹进行跟踪。

可以在设计阶段检测顶梁端点的最大水平变动量是否在规定的范围内。

为液压支架四连杆机构的设计提供参考依据,从而保证设计的合理性。

(2)利用UG/motion模块可以获得精确的仿真结果。

在进行产品设计或机构开发设计时,应综合应用UG各个模块的优势,把零件建模、装配和运动仿真有机结合起来,发挥软件最大功能。

参考文献:
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出版社,2005.
[2]王国法,等.液压支架技术[M].北京:煤炭工业出版社,1999.
[3]丁绍南.采煤工作面液压支架设计[M].北京:世界图书出版社,
1992.
[4]王国彪,饶明杰.液压支架优化设计与计算机模拟分析[M].北
京:机械工业出版社,1994.
[5]高悦.综采放顶煤液压支架四连杆机构CAD的研究与开发[D].
徐州:中国矿业大学,2002,5.
[6]徐新国,梁卫民.液压支架顶梁运动轨迹的计算方法[J].煤矿机
电,2004(4):6-8,11.
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矿业学院学报,1991,10(3):49-53.
Three-dimension Model and Dynamic Animation of Four-bar
Mechanism of Hydraulic Support
Abstract:UsingUG/motion rapidlysets up thewhole model ofthe hydraulic support, then simulatingthe risingand declining process with the UG/animation, at the same time to assure whether the maximal horizontal dis-placement movement is accordwith the design requirementor not, utilizingthe markerto trace the end pointofthe roof beam.
Key words:hydraulic support; four-bar mechanism; three-dimension model; dynamic animation
大采高强力液压支架的参数确定及结构设计
摘要:大采高强力液压支架是针对神东煤田浅埋深、薄基岩、厚风积沙等特定地质条件而研制的一种高性能综采液压支架。

本文对该类支架的工作阻力、初撑力、支护高度等主要参数进行了分析计算,并对其主要结构进行了设计。

关键词液压支架工作阻力结构设计
1 前言
神东煤田煤层埋深浅、基岩薄、上覆厚松散沙层,顶板岩层破断运动具有明显的特殊性,这种类型的浅埋煤田在世界上较为少见,因而对该类型煤层顶板岩层的控制几乎没有可借鉴的成熟理论和适用的支护设备。

从1991年起,神东煤炭公司相继对多个普采工作面和综采工作面进行了矿压观测,研究浅埋深煤层顶板的矿压显现规律,在建立了一整套厚风积沙、浅埋深煤层矿压理论,充分掌握“支架-围岩”相互作用关系后,分别与德国DBT公司和英国JOY公司合作,研制出了适应神东煤田采场矿压特点,满足高产高效型综采工作面煤层顶板支护要求的高性能综采液压支架。

2 支架主要技术参数确定
2.1 工作阻力
浅埋煤层工作面在初次来压和周期来压期间,顶板结构都将出现滑落失稳,老顶难以形成自
身稳定的岩梁结构,支架主要承受结构失稳形成的压力,最危险状态的载荷是“给定失稳载荷”状态。

支架工作阻力根据该矿压理论计算确定。

(1)老顶初次来压期间的支护阻力计算
支架必须提供的支护阻力Pm0由直接顶岩柱重量W和老顶结构滑落失稳所传递的压力
RD0组成,即
Pm0=W+RD0
作用于支架的直接顶岩柱重量为
W=LkbΣhρg
式中Lk——控顶距长度;
b——支架宽度;
Σh——直接顶厚度;
ρg——岩石视密度。

老顶结构滑落失稳传递压力为
RD0≥b(l01ρg+KG0h1l01ρ1g) 0.54 -0.24i- sinθ1
式中KG0——初次来压时载荷传递系数,
KG0=l01/(2h1λtanΦ)Kt0;
Φ——载荷层内摩擦角;
λ——载荷层侧应力系数;
Kt0——载荷传递的时间因子;
l01——老顶岩块长度;
ρg——老顶关键层视密度;
h1——载荷层厚度;
ρ1g——载荷层平均视密度;
θ1——断裂岩块回转角;
i——块度(岩块厚度与长度之比)。

所以,初次来压期间控制顶板所需要的
支护阻力Pm0≥lkbΣhρg+b(hl01ρg+KG0h1l01ρ1g) [0.54 - 0.24/(i- sinθ1)] (1)
(2)老顶周期来压期间的支护阻力计算
顶板在"台阶岩梁"结构形式下,支架必须提供
的支护阻力Pm由直接顶岩柱重量W和老顶结构
滑落失稳所传递的压力RD组成,即
Pm=W+RD=LkbΣhρg+RD
老顶结构滑落失稳作用到支架上的压力为
RD≥bP1(i- sinθ1max+ sinθ1- 0.5)i- 2sinθ1max+ sinθ1
式中P1——老顶关键块载荷。

则周期来压期间控制顶板所需的支护阻力为
Pm≥lkbΣhρg+bP1(i- sinθ1max+ sinθ1- 0.5)i- 2sinθ1max+ sinθ1 (2)
支护阻力Pm0和Pm是指为了维持工作面顶板
稳定,支架必须提供给顶板的有效支撑力,支架工
作阻力必须考虑支架的支护效率。

两柱支顶掩护式
液压支架的支护效率一般取0.8~0.9。

支架设计中,真正采用的工作阻力是根据对支
架总体结构参数的优化,不断进行修正的参数值,
最终目标在于满足维持工作面顶板稳定所需要的
支护阻力Pm0和Pm要求。

神东矿区五种两柱掩护
式液压支架的工作阻力为6715~8638 kN,分别适
用于不同条件的综采工作面。

2.2 初撑力
初撑力的主要作用是压缩浮矸浮煤,实现液压
支架对顶板的主动支撑,防止顶板过早离层破碎。

根据神东矿区浅埋深煤层的地质条件,大采高液压
支架的初撑力可按下式计算:
P=K[LkHγ+H2γctgθ/2] (3)
式中P——支架初撑力,kN/m;
Lk——支架控顶距,m ;
H——顶板一次冒落的岩层厚度,m;
γ——顶板岩石容重,kN/m3;
θ——顶板岩石破断角,根据观测确定;
K——冲击载荷系数,取K=1.2~1.3。

考虑支架的防冲击性能及工作面供液效率、液
压控制元件运行可靠性等因素的影响,支架设计初
撑力一般要比计算参考值略大。

2.3 支护高度
支架最大高度Hmax:由工作面煤层最大采高
hmax确定,同时考虑200~250 mm的顶板冒落高度
预量。

Hmax=hmax+ (200 ~ 250)
支架最小高度
Hmin=hmin-s-a-b(5)
式中hmin——煤层最低开采高度,mm;
s——支架顶梁后部顶板最大下沉量,取s=
150~200 mm;
a——支架前移时,立柱必须的下降高度,取
a=50~150 mm;
b——支架与煤层顶、底板间的浮煤、浮矸厚
度,取b=100 mm。

同时,在选择两柱掩护式支架的最大和最小高度时,尽可能地考虑了保持工作面煤层实际开采厚度范围与支架最佳工作高度范围一致。

确定支架最小高度还考虑了神东矿区井下支架运输工具和辅助运输巷道断面的高度,神东矿区综采液压支架采用支架搬运车运输,最低高度控制在2.5 m以下。

2.4 顶梁端面距
液压支架顶梁端面距可通过计算采煤机、输送机、液压支架三者的配套尺寸链予以精确确定。

神东矿区工作面开采后,顶板基岩沿全厚度切落,工作面极易形成台阶下沉,因而,在满足设备配套要求的前提下,设计尽可能缩小支架顶梁端面距,一般控制在350~450 mm范围内,以利于对采煤机机道处的顶板管理,
3 支架主要构件的设计
3.1 结构件设计
支架主体结构件(顶梁、掩护梁、底座、连杆等)均通过有限元应力分析,并采用STE700级高强度钢板制造(使用量约占支架自重的70%以上),结合国外先进的焊接加工工艺,使支架
结构件强度高,可靠性大,重量轻。

整体顶梁:箱形焊接结构,结构简单,对顶板载荷平衡能力强。

神东矿区高产高效综采工作面配套大槽宽(内宽1000 mm)刮板输送机和大截深(865 mm)
电牵引采煤机,因而支架顶梁在立柱柱帽前部无支撑段长,会造成顶梁前部对顶板支护能力弱,设计决定采用整体顶梁,而且将顶梁梁体前部设计为弹性上翘结构,可显著提高顶梁前端对顶板的支护力。

顶梁配置双向弹性活动侧护板,提高对顶板覆盖率,减少架间漏矸,改善支护效果,同时弹性活动侧护板也有利于防止大采高支架横向倾倒,提高支架稳定性。

掩护梁:采用整体箱形焊接结构,充分考虑了大采高支架复杂的三维空间受力,以及垮落顶板对梁体可能
造成的冲击破坏,安全系数大,强度高。

配置双向弹性活动侧护板,减少架间漏矸和防止大采高支架横向倾倒。

四连杆:双前连杆,单后连杆布置方式,连杆为箱形焊接结构,抗扭转能力强。

销轴与销孔最大配合间隙控制在1mm以内,以提高大采高液压支架稳定性。

底座:分体式钢性结构。

由于中挡底板分体,推移装置处的浮煤、浮矸可随支架移架从后端排到采空区,不需要人工清理,适应高产高效生产要求。

3.2 立柱、千斤顶设计立柱为双伸缩双作用式,推移千斤顶采用固定活塞式结构。

在保证结构需要前提下,考虑了不同型号支架立柱、千斤顶零部件的通用性与互换性,为设备维护、大修工作的配件准备提供便利。

3.3 护帮机构设计
神东矿区高产高效综采面采高都在4 m以上,开采后,顶板基岩沿全厚度切落,沿推进方向在煤壁上方会形成支承压力升高区,诱发煤壁片帮和梁端顶板冒落,因此全部支架都设计了四
连杆护帮机构,采用两根Φ90/63双作用油缸和液控双向锁控制。

3.4 提底座机构设计
两柱掩护式支架的主要缺点是底座前端对底板比压大,神东矿区高产高效综采面配套大槽宽
(内宽1000 mm)刮板输送机和大截深(865 mm)电牵引采煤机,支架顶梁在立柱柱帽前部段较长,加剧了支架底座前端对底板比压,造成底座容易扎底,影响支架移架速度。

在支架底座前桥后部设计提底座机构(如图2所示),能够大幅度地降低底座前部对底板的比压。

移架时,通过电液控制系统的程序控制,首先将底图2 提底装置对底座载荷的影响座前部抬起(提底座油缸为Φ125/90规格),再移架,显著改善了支架对工作面底板条件的适应能力,提高移架速度。

3.5 推移机构设计
神东矿区高产高效综采面配套重型刮板输送机,支架自重也达到21~25 t,对支架推移千斤顶的推拉力要求较高。

设计选用Φ150/100规格推移千斤顶,最大行程960 mm,推移千斤顶内部安装位移传感器,采用位移、时间双重因素控制支架拉架过程。

推移机构采用推移千斤顶倒装形式,配套整体箱式长推移杆。

参考文献:
[1] 王永东,田银素.大采高液压支架使用中存在的问题与对策[J].煤炭科学技术,2002,30(增刊):47-49.
[2] 王锦,王招.ZZ7200/20.5/34型支撑掩护式液压支架设计研究[J].煤矿机械,2000,(7):5-6.
[3] 罗恩波.国内外液压支架现状及我国的发展趋势[J].煤矿机电,2000,(3):27-29.
[4] 王俊杰,褚东升.综采液压支架初撑力有关问题的探讨[J].
矿山压力与顶板管理,2001,(2):6-8.
(上接第71页)
大于采高,可作为平衡岩层。

按照围岩平衡法,四层煤层处于覆岩平衡岩层
上部,距离平衡岩层还有10 m左右的层间距离,
满足上行开采条件。

综上所述,二、四层层间距离及岩性满足上行
开采的基本条件。

3.3 实施效果
孙村矿3218.19工作面自2000年4月开始掘
进,巷道基本上不受应力影响,支护无任何变化。

10
月投产后,工作面由于应力较低,工作面顶板管理
状况明显好转。

推进速度加快,单产单进有了较大幅度的提高。

4 结论
(1)上行开采可有效解决下行开采时二层煤
工作面推进速度慢,制约四层煤开采和矿井接续问
题,同时实现二、四层煤的高效开采,大幅度提高矿
井和矿区的高产高效生产水平。

(2)上行开采,可显著降低具有强烈冲击倾向
性的二层煤开采中的冲击地压危险程度,有效防治
深井开采时的冲击地压灾害。

(3)上行开采可有效解决二层煤工作面复合
顶板管理难的问题,大幅度提高二层煤开采的技术
效果和经济效益。

Application of the humid stress theory on the soft surrounding rock stability control around coal mining roadway——MIAO Xie-xing etc.
Based on mineral composition analysis of soft rock floor in east Xuzhou Mining Area, specimen test of swelling rock and deforma-tion measurement of surrounding rock are carried out, and the rela-tion of the rock properties and deformation of soft rock roadway are obtained. Analysis on the softening and swelling of surrounding rock under wetting action is done. Results come into good use in stability control of roadway surrounding rock.
Numerical simulation research of reasonable width of coal pillars in fully mechanized sublevel caving coalface with steep gradient——ZHANG Kai-zhi etc. No.12010 coalface is the first one in No.2 mining area of No.13 coalmine, which is a new, Pingtingshan mining group corporation, the maximum dip angle of coal seam is 32 degree. It is of first important problem that reasonable width of coal pills should be determined to the arrangement of coal mining and tunneling with steep gradient. By numerical calculation of breaking zone, displacement and deformation of both side roadways, abutment pressure of coal pillars are obtained. The results indicate that reasonable width of coal pillars is 8m, which is only half of the design value.
Investigation for roadway support forms and surrounding rock
deformation in deep-lying seam——LI Xing-dong etc.
By means of investigating surrounding rock deformation of two roadways support forms in deep mining for Xinwen coal mine area,and after studying probability distributing of surrounding rock deformation under rock bolting pattern, the applicability of two support patterns under different conditions is analyzed, and the rules of surrounding rock deformation under rock bolting patterns is obtained. It is of directive signification for choose roadway support forms of deep mining and support parameters for Xinwen coal mine area.
Trial study on full-length recoverable cement metal bolt——
KANG Quan-yu etc.
Considering the characteristics of the mine gateway, full-length recoverable cement metal bolt applicable to wall support in the mine gateway was designed and developed. Industrial test shows that the bolt is simple in structure, big in anchorage force, easy and
quick in recovery, and low in cost, and that no bolt metal is left in coal to have small influence upon coal winning machines, and the recovery rate is high; thus being a promising support material in coal road and having remarkable social and economic benefit.
Theory analysis and engineering practice of reinforcing soft
surrounding rock roadway with bolting——TANG Duan-jian
The theory of strengthening surrounding rock supported with
bolting is applied in this paper. Then the strengthening model of
mechanics parameters of bolting body is established. Because of
strengthening surrounding rock by bolting, a high load-bearing ca-
pacity structure around the roadway can be formed when applying
bolt to reinforce soft surrounding rock. Thus the roadway can be
kept stable. On the basis of this principle, the parameters of rein-
forcing project are calculated and they are applied in engineering
practice.
The ground behavior regularity of conventional caving method
coal face on soft seam with soft surrounding and study of the appro-
priate support patterns——WANG Yong-jian
Based on mining tests on the prop and?πpattern girder caving
method with full shear height, analysis and studies the ground be-
havior regularity of conventional caving method coal face on soft
seam with soft surrounding and extremely unstable seam have been
performed. Experiment and study the appropriate support patterns
and support parameters have been carried out. Practice and study
has confirmed that the prop caving method with full shear height on
soft seam with soft surrounding and extremely unstable soft seam is
an adapted mining technique with high output and high efficiency.
The application of numerical simulation in big dip angle and
hard roof control——YIN Zeng-de etc.
Simulation calculation on surrounding rock stress distribution
and displacement characteristics is made by means of coupling FEM
and BEM under the condition of big deep angle and hard roof. The
results are applied in situ observation and practice. The method has
been proved to have directing meanings for ground pressure and
safety production。

Characteristics of ground pressure behavior in hard thick-top- coal fully mechanized caving face——LI Zhen-ming etc.
Upon the site observing data, this paper analyzes the character-
istics of ground pressure behavior in hard thick-top-coal fully mech-
anized caving face. Research results indicate that the support loads
of the face is greater than that of the slicing fully mechanized mining
face, the periodic ground pressure in this face appears in evidence,
and pre-weaken the hard-top-coal obviously influences the ground
pressure behavior of the face.
Research of coal seam floor's fracture depth of fully-mecha-
nized mining face——LI Hai-mei etc.
Based on in-situ stress measurement, by usage of the method
of combined theoretical calculation with finite-element simulation, it
is calculated No.9 coal seam floor' s failure depth in Xiandewang
Coal Mine. We provide the equation of the coal seam floor' s failure
depth.
Parameters determination and structure design of high mining
height hydraulic support——YUE Wen-hui
The high mining height hydraulic support is designed for the
special geologic condition of Shendong coalfield, such as shallow
buried depth, thin bedrock and thick aeolian sand. The main param-
eters of the hydraulic support, such as working resistance, setting
load and support height, are analyzed and its main structures are de- sign.
The characteristic and prediction of the surficial movement and displacement under the minimal working face mining——LIU Shu- can etc.
There are enormous coal pressed by villages in the field of Fengfeng Bureau of Mine, which is related to some great problems includes the mine' s life span and the enterprise' s sustainable devel- opment. Therefore, there are profound meanings in finding the ex- perience and measurements which resolve these problems. Using the phenomenon that the surficial movement and displacement will greatly reduce under the minimal working face mining, the author has resolved some problems about coal mining under villages and obtained some measurement data. The article does some researches and analysis in the characteristics of the measured movement and displacement and the predication computation. The founding shows the prediction computation of the surficial movement and displace- ment still can employ probability integral method, but the subsi- dence coefficient should be amended. The article gives the amend- ment formula of the subsidence coefficient.
Loose relieving shot technology of ultra-deep hole in gas logged coal road proving——LU Yuan etc.
This article study the coal-and outburst theory and its hazard in high gas mine coal road driving of Huainan mining area, and study to use of the ultra-deep hole loose relieving shot to select blasting parameters, constructional measurement and some cases that must be noticed to deal with gas.
Design of ground pressure observational meshwork of Xinqiao Pyrites Mine——XIAO Zhi-zheng etc.
After analyzing the present situation geology and mine of Xin-
qiao Pyrites Mine, the author points out the necessity of the con- struction of observational meshwork, and particularly introduces the composing of observational meshwork of Xinqiao Pyrites Mine, the arrange of observation station, the manufacture of point down well, the combine measure of those points and the observation of rock body. At last the author gave some suggestions on these obser- vation and brought an example for the construction of similar mesh- work.
Study on predicting rock burst according surface subsi- dence——TANG Ju-peng etc.
In view of the situation that rock burst happens frequently in
our country now, the inner characteristics of surface subsidence and rock burst are discussed in this paper. Based upon Huafeng coal mine as an example, it points out that there is a basic corresponding relation between surface subsiding velocity and rock burst in a new view, which have inverse-spring effect, wave band effect, lagging character. The rule of the relation is summarized and numerical ana- lyzed which will contribute to the prediction and prevention of rock burst. The conclusion of theory study and numerical simulation will play roles in rock burst research in the future.
Research on T-shaped High Strength Concrete Members Sub- jected to Axial Compression and Biaxial bending——FAN Wei etc. Based on the experimental study of 9 high strength concrete members with T-shaped cross section subjected to axial compression
and biaxial bending. This paper reveals the failure pattern, the cal- culation results coincides with the experimental result well. The variation regularity of bearing capacity of T-shaped member is ob- tained.。