隧道开挖ansys模拟分析 - 图文 下载本文

隧道台阶法开挖的有限元模拟分析

1.力学模型的建立

岩体的性质是十分复杂的,在地下岩体的力学分析中,要全面考虑岩体的所有性质几乎是不可能的。建立岩体力学模型,是将一些影响岩石性质的次要因素略去,抓住问题的主要矛盾,即着眼于岩体的最主要的性质。在模型中,简化的岩体性质有强度、变形、还有岩体的连续性、各项同性及均匀性等。考虑岩石的性质和变形特性,以及外界因素的影响,采用的模型有弹性、塑性、弹塑性、粘弹性、粘弹塑性等。

根据对隧道的现场调查及试验结果分析,围岩具有明显的弹塑性性质。因此,根据隧道的实际情况,考虑岩体的弹塑性性质,在符合真实施工工序和支护措施的基础上,在数值模拟过程中将计算模型简化成弹塑性平面应变问题,采用Drucker—Prager屈服准则来模拟围岩的非线性并且不考虑其体积膨胀,混凝土材料为线弹性且不计其非线性变形。

对地下工程开挖进行分析,一般有两种计算模型: (1)“先开洞,后加载”

在加入初始地应力场前,首先将开挖掉的单元从整体刚度矩阵中删除,然后对剩余的单元加入初始地应力场进行有限元计算。 (2)“先加载,后开洞”

这种方法是首先在整个计算区域内作用地应力场,然后在开挖边界上施加反转力,经过有限元计算得到所需要的应力、位移等物理量。

两种方法对线弹性分析而言,所得到的应力场是相同的,而位移场是不同的,模型(2)(即:“先加载,后开洞”)更接近实际情况。在实际地下工程开挖中部分岩体已进入塑性状态,必须用弹塑性有限元进行计算分析,而塑性变形与加载的路径有关,所以模拟计算必须按真实的施工过程进行,即在对地下工程开挖进行弹塑性数值模拟过程中,必须遵循“先加载,后开洞”的原则。

在有限元法中,求解非线性问题最常采用的方法是常刚度初应力法。对于弹塑性问题,由于塑性变形不可恢复,应力和应变不再是一一对应的关系,即应力状态与加载路径有关,因此应该用增量法求解。弹塑性应力增量与应变增量之间的关系可近似地表示为

d{?}?[Dep]d{?}?([D]?[Dp]){d?}?[D]{d?}?d{?0} (1) 式中,[D]—弹性矩阵,[Dp]—塑性矩阵。

d{?0}??[D]pd{?} (2) [D]?p[D]{?F?FT}{}[D]???? (3) ?F?F{}T[D]{}????式(6.54)中,F—屈服函数。

d{?0}为初应力。由于线性化,式(6.52)可以表示为:

?{?}?[D]?{?}??{?0},?{?0}??[D]p?{?} (4) 位移增量所满足的方程为

[K]?{?}??{F}??{F0},?{F0}??[B]T[D]p?{?}dV (5) 式中,[K]—刚度矩阵,[B]—应变矩阵。

按式(6.56)计算时,应将荷载分为若干个增量步,在每一增量步均按下式进行迭代计算:

[K]{?}i?1?{F}?{F0}i, {F0}i??[B]{?0}dV (6) 迭代计算直到初应力接近零值时再施加下一步增量荷载。

T2. 围岩及结构物理力学参数

张涿高速公路是一条绕行北京、连接张家口市与西北各省区及京津地区的快速通道,其全线共设置隧道36座,其中,保定段LJ-S5合同段共设置隧道三座,均为分离式隧道,通过实地考察,并参考图纸,选取隧道YK91+334作为典型试验断面,该隧道埋深35m~45m,采用双车道,隧道净宽12.75m,高5米,隧道拱周边为L=4m,纵、环向间距75cm×75cm呈梅花桩布置的锚杆加固围岩。

在计算过程中,根据隧道围岩和支护结构的物理力学指标,结合铁路隧道、公路隧道设计规范及相关规范加以选取。在隧道支护体系中,超前支护的刚度和周围岩体相差较大,而超前支护的真正作用是在施工过程中起到及时加固、限制塑性区的发展、使围岩能够保持较好的连续性和整体性,从而使围岩能够很好地起到自承作用,故在数值模拟时对超前支护常采用提高围岩c、φ值的方法进行

概化处理,即采用将超前支护加固圈地层力学参数适当加大的方法来模拟地层超前支护。根据试验结果,所确定的具体参数如表1所示。

表1 围岩及隧道结构物理力学参数

材料 围岩 衬砌 锚杆 弹性模量 (GPa) 1.3 27.5 200 泊松比 0.30 0.20 0.30 岩体重度 (kN/m3) 2450 2500 7960 内聚力 (MPa) 0.15 2.42 内摩擦角 (°) 39 54

3.计算采用的材料屈服准则

计算采用弹塑性平面应变模型。岩土材料的非线性按DP材料处理,在ANSYS程序中,DP材料选项使用Drucker-Prager屈服准则,此屈服准则对Mohr-Coulolnb准则给予近似,以此来代替Mohr-Coulomb准则。其流动准则可以使用相关流动准则也可以使用不相关流动准则,其屈服面并不随着材料的逐渐屈服而改变,因此没有强化准则,然而其屈服强化随着侧限压力的增加而相应增加,其塑性行为被认为是理想弹塑性。另外,作为岩体的两个重要的参数内聚力c和内摩擦角φ都能通过材料数据表输入。

4.计算步骤及程序的实现

数值计算的基本思路是:将整个开挖、支护过程设置为若干个荷载步,在各个荷载步中实现岩体开挖、支护等步骤,并逐一求解,直至最终形成围岩—支护体系为止。具体步骤:

① 隧道开挖之前,在岩体荷载作用下对模型进行平衡计算,这是对模型进行的第一步求解,得围岩的初始应力分布。

② 为实现隧道开挖过程,将上台阶代表被开挖掉的岩体和喷射混凝土层的单元一同杀死,对模型进行第二步求解。

③ 为实现喷射混凝土支护的过程,将上台阶代表喷射混凝土层的单元复活,并改变其材料属性,对模型进行第三步求解。

④为实现隧道开挖过程,将下台阶代表被开挖掉的岩体和喷射混凝土层的单元一同杀死,对模型进行第四步求解。

⑤为实现喷射混凝土支护的过程,将下台阶代表喷射混凝土层的单元复活,并改变其材料属性,对模型进行第五步求解。

5.ANSYS模型的建立

根据张涿高速公路南宫一号隧道的相关尺寸,对有代表性断面,建立二维弹塑性有限元计算模型。模型计算范围在水平方向宽度取大于隧道宽度的6倍(90m ),下边界取洞高的2倍(16m),上边界可取隧道的实际埋深(40m)。模型的边界条件采用施加约束的方法,在模型的底面加Y方向的位移约束,在隧道两侧的边界上施加x方向的位移约束以模拟岩体的沉降。岩体和混凝土使用ANSYS程序中的二维四节点等参单元PLANE42模拟,锚杆用平面杆单元LINK 1来模拟,喷射混凝土采用梁单元BEAM3模拟。有限元计算模型如图1所示。

图1 计算模型网格划分

6.单元划分

(1)整体网格划分及单元划分如下图所示:

整体网格划分及单元划分

(2)计算过程:加自重计算后

自重作用下水平方向位移云图 自重作用下竖直方向位移云图

自重作用下水平方向应力云图 自重作用下竖直方向应力云图

自重作用下第一主应力云图 自重作用下第三主应力云图

(2)隧道上台阶开挖后(即开挖土体1后)

隧道上台阶开挖后模型 隧道上台阶开挖后水平方向位移云图

隧道上台阶开挖后竖直方向位移云图 隧道上台阶开挖后水平方向应力云图

隧道上台阶开挖后竖直方向应力云图 隧道上台阶开挖后第一主应力云图

隧道上台阶开挖后第三主应力云图 隧道上台阶初期支护轴力图

隧道上台阶开挖后初期支护剪力图 隧道上台阶开挖后初期支护弯矩图

(3)隧道下台阶开挖后

隧道下台阶开挖后模型 隧道下台阶开挖后水平方向位移云图

隧道下台阶开挖后竖直方向位移云图 隧道下台阶开挖后水平方向应力云图

隧道下台阶开挖后竖直方向应力云图 隧道下台阶开挖后第一主应力云图

隧道下台阶开挖后第三主应力云图 隧道下台阶初期支护轴力图

隧道下台阶开挖后初期支护剪力图 隧道下台阶开挖后初期支护弯矩图

7.结果分析

(1)隧道周围的围岩位移

从变形图和位移图可以看出,隧道在开挖过程中,再不做二衬的情况下,总的拱顶下沉在4.2959cm左右,两侧边墙的水平位移最大值在1.2cm左右。隧道周围的围岩中的移动趋势:拱顶下沉、两侧边墙张开,同时围岩在拱顶部分形成一个“V”型槽。总的来说,从隧道周围变形的情况看,采用上下台阶法开挖修建此隧道是安全的,围岩基本能够稳定,同时要及时做二衬加固。 (2)隧道周围的围岩应力

从各个方面地层应力图以及主应力图可以看出,随着隧道的开挖修建,整个

地层大部分区域都是受压的,只是在隧道附近一个很小的区域范围内出现拉应力。同时从图中可知,拉应力区域都在所加固的围岩范围以内,因此说明,本隧道设计中,所采用的加固措施是合理的,并且是有效的。从整个应力图可以得出,所设计的初期支护参数能基本满足施工过程中围岩的稳定。 (3)衬砌结构的变形和内力

从初衬砌结构的变形和内力可以看出,边墙的轴力比较大,有可能出现应力集中的现象。所以,建议在施工过程中,应在拱角处打锁角锚杆,并适当加厚此处的衬砌结构,同时还有采用配钢筋的混凝土作为二次衬砌来满足设计要求。

命令流:

finish /clear

/COM,Structural ! 指定结构分析 /TITLE,Tunnel Construct Modeling Analysis ! 定义工作标题

/FILNAM,support,1 !锚杆

MP,EX,4,200E9 MP,PRXY,4,0.3 MP,DENS,4,7960 !定义实常数

R,1,0.3,0.3*0.3*0.3/12,0.3, !衬砌支护实常数

! 定义工作文件名 !进入前处理器 /PREP7

!定义单元类型

ET,1,BEAM3 !定义衬砌支护单元

KEYOPT,1,6,1 局部坐标系输出力、弯矩

ET,2,PLANE42 !定义围岩单元

KEYOPT,2,3,2 ! Plane strain

ET,3,LINK1 !定义LINK1单元 !定义材料属性 !衬砌支护

MP,EX,1,2.75E10 MP,PRXY,1,0.2 MP,DENS,1,2500

TB,DP,1 !采用D-P模型 TBDATA,1,2.42E6,54 !围岩材料

MP,EX,2,1.3E9 MP,PRXY,2,0.3 MP,DENS,2,2450 TB,DP,2

TBDATA,1,0.15E6,39 !内粘聚力 内摩擦角 !挖去土体材料 MP,EX,3,4.5E8 MP,PRXY,3,0.3 MP,DENS,3,2450 TB,DP,3

TBDATA,1,0.1E6,24.3

R,2,3.14*0.025*0.025/4,, !锚杆实常数 NUMSTR,KP,1 NUMSTR,LINE,1 NUMSTR,AREA,1 NUMSTR,VOLU,1 !CSYS,0 k,1,0,14.475 k,2,0,-3.525

k,3,5.6098,-2.6285 k,4,1.4247,-3.4685 k,5,5.1423,-1.2032 k,6,6.6179,-1.4726 k,7,5.9709,-2.4536 k,8,-1.4488,0 k,9,6.7512,0

k,10,6.6761,-1.1071 k,11,0.9012,0

k,12,4.8631,4.3042 k,13,6.6267,1.2006 k,14,0,-0.9791 k,15,0,6.2016

k,16,3.8021,5.1124 k,17,0,-7.525

k,18,6.8564,-6.4293 k,19,1.7413,-7.456 k,20,10.5529,-2.191 k,21,8.1805,-5.7879 k,22,10.7512,0

k,23,10.6395,-1.6472 k,24,7.572,7.2473 k,25,10.5415,2.0215 k,26,0,10.2016 k,27,5.9201,8.5057 k,28,-4.8631,4.3042

k,29,-1.3279,6.0778 k,30,-0.9012,0 k,31,-6.7512,0

k,32,-5.6621,3.3995 k,33,1.4488,0

k,34,-6.6179,-1.4726 k,35,-6.7429,-0.37 k,36,-5.1423,-1.2032 k,37,-5.6098,-2.6285 k,38,-6.4937,-1.8542 k,39,-4.2384,-3.0189 k,40,-6.8564,-6.4293 k,41,-5.1803,-6.9064 k,42,-10.5529,-2.191 k,43,-10.0974,-3.5901 k,44,-10.7512,0

k,45,-10.7388,-0.5505 k,46,-7.572,7.2473 k,47,-8.9174,5.7239 k,48,-2.0677,10.0088 k,49,12.8586,50 k,50,29.6587,50 k,51,45.6987,50 k,52,0,0

k,53,-46.4587,50 k,54,-12.8512,50

k,55,-12.8512,12.3016 k,56,-46.4587,12.3016 k,57,-12.8512,-9.625 k,58,-46.4587,-9.625 k,59,-12.8512,-25.525 k,60,-46.4587,-25.525 k,61,12.8586,-25.525 k,62,12.8586,-9.625 k,63,12.8586,12.3016 k,64,45.6987,-25.525 k,65,45.6987,-9.625 k,66,45.6987,12.3016 k,67,0,12.3016 k,68,0,-9.625 k,69,12.8586,0 k,70,-12.8512,0 l,49,50, l,50,51, l,31,52, l,52,9, l,53,54, l,55,56, l,57,58, l,59,60, l,59,61, l,57,62, l,55,63, l,54,49, l,61,64, l,62,65, l,63,66, l,51,66, l,66,65, l,65,64, l,60,58, l,58,56, l,56,53, l,59,57, l,57,55, l,55,54, l,61,62, l,62,63, l,63,49, l,26,67, l,17,68, l,22,69, l,44,70, LARC,2,3,4 LARC,3,6,7 LARC,6,9,10 LARC,9,12,13 LARC,12,15,16 LARC,17,18,19 LARC,18,20,21 LARC,20,22,23 LARC,22,24,25 LARC,24,26,27 LARC,15,28,29 LARC,28,31,32 LARC,31,34,35 LARC,34,37,38 LARC,37,2,39

LARC,40,17,41 LARC,42,40,43 LARC,44,42,45 LARC,46,44,47 LARC,26,46,48 AL,5,24,6,21 AL,12,27,11,24 AL,1,2,16,15,27

a,56,60,64,66 !通过4个关键点生成一个面积区域

asbl,all,all !通过线分割面生成新面

adele,4 !删除面 NUMCMP,AREA !压缩面编号 !生成锚杆

asel,s,,,15 !选择面15

csys,1 !激活柱坐标系

wprota,,-90 !工作平面绕X轴旋转-90度

*do,i,1,30,1 !循环控制

wprota,,,-6 !工作平面绕Y轴旋转-6度asbw,all !用工作平面切割所选择的所有面 *enddo

Lcomb,89,92,0 Lcomb,186,190,0 Lcomb,64,70,0 Lcomb,82,77,0 Lcomb,204,199,0 Lcomb,211,216,0 Lcomb,99,95,0 Lcomb,181,185,0 Lcomb,49,65,0 Lcomb,36,101,0 Lcomb,178,187,0 Lcomb,223,217,0

l,55,157 l,57,96 l,62,155 l,63,98 allsel !删除面

FLST,2,4,5,ORDE,2 FITEM,2,10 FITEM,2,-13 ADELE,P51X !生成面

FLST,2,11,4 FITEM,2,60 FITEM,2,28 FITEM,2,146 FITEM,2,152 FITEM,2,158 FITEM,2,164 FITEM,2,170 FITEM,2,176 FITEM,2,182 FITEM,2,181 FITEM,2,65 AL,P51X FLST,2,10,4 FITEM,2,56 FITEM,2,65 FITEM,2,194 FITEM,2,200 FITEM,2,197 FITEM,2,212 FITEM,2,209 FITEM,2,214 FITEM,2,227 FITEM,2,31 AL,P51X FLST,2,10,4 FITEM,2,31 FITEM,2,26 FITEM,2,49 FITEM,2,72 FITEM,2,78 FITEM,2,84 FITEM,2,90 FITEM,2,87 FITEM,2,70 FITEM,2,57 AL,P51X

FLST,2,11,4 FITEM,2,36 FITEM,2,41 FITEM,2,104 FITEM,2,110 FITEM,2,116 FITEM,2,122 FITEM,2,128 FITEM,2,143 FITEM,2,29 FITEM,2,58 FITEM,2,70 AL,P51X FLST,2,11,4 FITEM,2,137 FITEM,2,37 FITEM,2,149 FITEM,2,155 FITEM,2,161 FITEM,2,167 FITEM,2,173 FITEM,2,178 FITEM,2,82 FITEM,2,59 FITEM,2,29 AL,P51X FLST,2,10,4 FITEM,2,82 FITEM,2,62 FITEM,2,30 FITEM,2,229 FITEM,2,217 FITEM,2,218 FITEM,2,202 FITEM,2,206 FITEM,2,43 FITEM,2,38 AL,P51X FLST,2,10,4 FITEM,2,92 FITEM,2,63 FITEM,2,30 FITEM,2,55 FITEM,2,40 FITEM,2,11 FITEM,2,68 FITEM,2,75 FITEM,2,80 FITEM,2,96 AL,P51X FLST,2,11,4 FITEM,2,28 FITEM,2,61 FITEM,2,92 FITEM,2,95 FITEM,2,100 FITEM,2,107 FITEM,2,113 FITEM,2,119 FITEM,2,125 FITEM,2,131 FITEM,2,141 AL,P51X

!划分网格生成有限元模型!划分梁单元

mat,1 !指定梁单元材料特性 type,1 Lsel,s,,,54 lsel,a,,,35 lsel,a,,,45,46 lsel,a,,,10 lsel,a,,,74 lsel,a,,,89

lsel,a,,,102,138,6 lsel,a,,,140 lsel,a,,,145 lsel,a,,,51

lsel,a,,,151,175,6 lsel,a,,,188 lsel,a,,,186 lsel,a,,,193 lsel,a,,,196 lsel,a,,,205 lsel,a,,,208 lsel,a,,,34 lsel,a,,,226 lsel,a,,,23

lsel,a,,,66 lsel,a,,,64 lsel,a,,,71 lsel,a,,,77 lsel,a,,,83 lsel,a,,,86 lsel,a,,,93 lsel,a,,,47 lsel,a,,,105 lsel,a,,,111 lsel,a,,,117 lsel,a,,,123 lsel,a,,,129 lsel,a,,,142 lsel,a,,,136 lsel,a,,,32 lsel,a,,,148 lsel,a,,,154 lsel,a,,,160 lsel,a,,,166 lsel,a,,,172 lsel,a,,,179 lsel,a,,,50 lsel,a,,,191 lsel,a,,,199 lsel,a,,,33 lsel,a,,,211 lsel,a,,,224 lsel,a,,,228 lesize,all,,,1 lmesh,all

mat,4 !指定锚杆单元材料特性 type,3 real,2

lsel,s,,,203 lsel,a,,,219 lsel,a,,,225 lsel,a,,,220 lsel,a,,,53 lsel,a,,,44 lsel,a,,,48 lsel,a,,,69 lsel,a,,,76 lsel,a,,,81 lsel,a,,,97 lsel,a,,,103 lsel,a,,,109 lsel,a,,,115 lsel,a,,,121 lsel,a,,,127 lsel,a,,,133 lsel,a,,,139 lsel,a,,,135 lsel,a,,,147 lsel,a,,,153 lsel,a,,,159 lsel,a,,,165 lsel,a,,,171 lsel,a,,,177 lsel,a,,,183 lsel,a,,,189 lsel,a,,,195 lsel,a,,,201 lsel,a,,,198 lsel,a,,,213 lsel,a,,,210 lsel,a,,,215 lsel,a,,,39 lsel,a,,,52 lsel,a,,,67 lsel,a,,,73 lesize,all,,,3 lmesh,all allsel

!划分开挖区 mat,3 type,2

FLST,5,2,4,ORDE,2 FITEM,5,3 FITEM,5,-4 CM,_Y,LINE LSEL, , , ,P51X CM,_Y1,LINE CMSEL,,_Y !*

LESIZE,_Y1, , ,10, , , , ,1 !*

MSHAPE,0,2D MSHKEY,0 !*

FLST,5,2,5,ORDE,2 FITEM,5,9 FITEM,5,14 CM,_Y,AREA ASEL, , , ,P51X CM,_Y1,AREA

CHKMSH,'AREA' CMSEL,S,_Y !*

AMESH,_Y1 !*

CMDELE,_Y CMDELE,_Y1 CMDELE,_Y2 !*

!划分加固区

mat,2 !赋予围岩单元属性 type,2

FLST,5,23,4,ORDE,23 FITEM,5,42 FITEM,5,79 FITEM,5,85 FITEM,5,88 FITEM,5,91 FITEM,5,94 FITEM,5,98 FITEM,5,106 FITEM,5,112 FITEM,5,118 FITEM,5,124 FITEM,5,130 FITEM,5,134 FITEM,5,144 FITEM,5,150 FITEM,5,156 FITEM,5,162 FITEM,5,168 FITEM,5,174 FITEM,5,180 FITEM,5,184 FITEM,5,192 FITEM,5,207 CM,_Y,LINE LSEL, , , ,P51X CM,_Y1,LINE CMSEL,,_Y !*

LESIZE,_Y1, , ,3, , , , ,1 !*

FLST,5,60,4,ORDE,59 FITEM,5,11 FITEM,5,26 FITEM,5,36 FITEM,5,-38 FITEM,5,40 FITEM,5,-41 FITEM,5,43 FITEM,5,49 FITEM,5,55 FITEM,5,68 FITEM,5,72 FITEM,5,75 FITEM,5,78 FITEM,5,80 FITEM,5,84 FITEM,5,87 FITEM,5,90 FITEM,5,95 FITEM,5,-96 FITEM,5,100 FITEM,5,104 FITEM,5,107 FITEM,5,110 FITEM,5,113 FITEM,5,116 FITEM,5,119 FITEM,5,122 FITEM,5,125 FITEM,5,128 FITEM,5,131 FITEM,5,137 FITEM,5,141 FITEM,5,143 FITEM,5,146

FITEM,5,149 FITEM,5,152 FITEM,5,155 FITEM,5,158 FITEM,5,161 FITEM,5,164 FITEM,5,167 FITEM,5,170 FITEM,5,173 FITEM,5,176 FITEM,5,178 FITEM,5,181 FITEM,5,-182 FITEM,5,194 FITEM,5,197 FITEM,5,200 FITEM,5,202 FITEM,5,206 FITEM,5,209 FITEM,5,212 FITEM,5,214 FITEM,5,217 FITEM,5,-218 FITEM,5,227 FITEM,5,229 CM,_Y,LINE LSEL, , , ,P51X CM,_Y1,LINE CMSEL,,_Y !*

LESIZE,_Y1, , ,1, , , , ,1 !*

FLST,5,60,5,ORDE,4 FITEM,5,15 FITEM,5,-72 FITEM,5,75 FITEM,5,-76 CM,_Y,AREA ASEL, , , ,P51X CM,_Y1,AREA

CHKMSH,'AREA' CMSEL,S,_Y !*

AMESH,_Y1 !*

CMDELE,_Y CMDELE,_Y1 CMDELE,_Y2 !*

!划分周围

mat,2 !赋予围岩单元属性 type,2

FLST,5,4,4,ORDE,2 FITEM,5,58 FITEM,5,-61 CM,_Y,LINE LSEL, , , ,P51X CM,_Y1,LINE CMSEL,,_Y !*

LESIZE,_Y1, , ,8, , , , ,1 !*

FLST,5,4,4,ORDE,4 FITEM,5,56 FITEM,5,-57 FITEM,5,62 FITEM,5,-63 CM,_Y,LINE LSEL, , , ,P51X CM,_Y1,LINE CMSEL,,_Y !*

LESIZE,_Y1, , ,7, , , , ,1 !*

FLST,5,8,4,ORDE,6 FITEM,5,28 FITEM,5,-31 FITEM,5,65 FITEM,5,70 FITEM,5,82 FITEM,5,92 CM,_Y,LINE LSEL, , , ,P51X CM,_Y1,LINE CMSEL,,_Y !*

LESIZE,_Y1, , ,3, , , , ,1 !*

amap,10,55,157,26,67 amap,11,55,157,44,70 amap,12,70,44,96,57 amap,13,96,57,68,17 amap,73,155,62,68,17 amap,74,155,62,69,22 amap,77,98,63,69,22 amap,78,98,63,67,26 FLST,5,2,4,ORDE,2 FITEM,5,17 FITEM,5,20 CM,_Y,LINE LSEL, , , ,P51X CM,_Y1,LINE CMSEL,,_Y !*

LESIZE,_Y1, , ,14, , , , ,1 !*

FLST,5,4,4,ORDE,4 FITEM,5,6 FITEM,5,-7 FITEM,5,14 FITEM,5,-15 CM,_Y,LINE LSEL, , , ,P51X CM,_Y1,LINE CMSEL,,_Y !*

LESIZE,_Y1, , ,16, , , , ,1 !*

amap,5,56,55,57,58 amap,8,62,63,66,65 FLST,5,3,4,ORDE,3 FITEM,5,8 FITEM,5,-9 FITEM,5,13 CM,_Y,LINE LSEL, , , ,P51X CM,_Y1,LINE CMSEL,,_Y !*

LESIZE,_Y1, , ,16, , , , ,1 !*

FLST,5,4,4,ORDE,4 FITEM,5,18 FITEM,5,-19 FITEM,5,22 FITEM,5,25 CM,_Y,LINE LSEL, , , ,P51X CM,_Y1,LINE CMSEL,,_Y !*

LESIZE,_Y1, , ,15, , , , ,1 !*

amap,3,58,57,59,60 amap,6,62,57,59,61 amap,4,62,65,64,61 FLST,5,4,4,ORDE,4 FITEM,5,16 FITEM,5,21 FITEM,5,24 FITEM,5,27 CM,_Y,LINE LSEL, , , ,P51X CM,_Y1,LINE CMSEL,,_Y !*

LESIZE,_Y1, , ,15, , , , ,1 !*

FLST,5,2,4,ORDE,2 FITEM,5,5 FITEM,5,12 CM,_Y,LINE LSEL, , , ,P51X CM,_Y1,LINE CMSEL,,_Y !*

LESIZE,_Y1, , ,16, , , , ,1 !*

FLST,5,2,4,ORDE,2 FITEM,5,1 FITEM,5,-2 CM,_Y,LINE LSEL, , , ,P51X CM,_Y1,LINE CMSEL,,_Y !*

LESIZE,_Y1, , ,8, , , , ,1 !* amap,1,53,54,55,56 amap,7,54,55,63,49 amap,2,51,66,63,49 !(3)施加约束和荷载 /SOLU !施加约束 csys,0 nsel,s,loc,x,-46.4587 !选择X=-52线上所有节点

nsel,a,loc,x,45.6987 !选择X=52线上所有节点

d,all,ux !对所选择节点约束X方向位移

allsel nsel,s,loc,y,-25.525 !选择Y=-65线上所有节点 d,all,uy !对所选择节点约束Y方向位移 !施加重力加速度

acel,,10 NSUBST,5,100,1 !设置求解步 NROPT,FULL, , !采用全牛顿—拉普森法进行求解 FINISH /PREP7 esel,s,mat,,1,4,3 !选择材料号为1、4的单元

ekill,all !杀死所选择的单元 esel,all esel,s,live !选择活单元 nsle,s !选择节点 nsel,inve !反选择当前节点

d,all,all !约束所选择节点、自由度

allsel /SOLU !进入求解器

/STATUS,SOLU ALLS !选择所有内容

SOLVE !求解计算 /POST1 !进入后处理器

PLDISP,1 !显示变形情况

PLNSOL,U,X,0,1 绘制水平方向位移云图

PLNSOL,U,Y,0,1 !绘制竖直方向位移云图 PLNSOL,S,X,0,1 !绘制水平方向应力云图 PLNSOL,S,Y,0,1 !绘制竖直方向应力云图 PLNSOL,S,1,0,1 !绘制第一主应力云图 PLNSOL,S,3,0,1 !绘制第三主应力云图 ESEL,S,,,411,428 !选择单元 ESEL,A,,,429,430 !补选单元 ESEL,A,,,608,626,6 ESEL,A,,,621,627,6

ESEL,A,,,450,453,3 ESEL,A,,,462,474,6

ESEL,A,,,483,531,6 ESEL,A,,,539,593,6 ESEL,A,,,596 ESEL,A,,,605 NFORCE,ALL,ALL !提取所选单元的节点力

FINISH !进行隧道上台阶开挖 /SOLU !进入求解器 ANTYPE,,REST,1 !重新启动求解器 esel,s,mat,,1,4,3 !选择材料号为1、4的单元 ekill,all !杀死所选择的单元

esel,all ESEL,S,,,172,350 !选择上台阶开挖土体单元 EKILL,ALL !对所选单元赋予“死属性” ESEL,S,LIVE !选择具“生属性”的单元

F,1,FX,114600 F,2,FX,107640

F,3,FX,-62520 F,9,FX,-113580

F,10,FX,-120180 F,11,FX,120120

F,12,FX,99420 F,13,FX,90300

F,14,FX,80460 F,19,FX,-4903.8 F,20,FX,-12900 F,21,FX,58818 F,28,FX,70620 F,29,FX,61380 F,31,FX,52530 F,33,FX,43884 F,35,FX,35442 F,37,FX,27174 F,39,FX,19074 F,41,FX,11034 F,42,FX,3046.8 F,44,FX,-21030 F,46,FX,-29352 F,48,FX,-37890 F,50,FX,-46680 F,52,FX,-55734 F,53,FX,-75720 F,54,FX,-65340 F,56,FX,-86280 F,57,FX,-96300 F,58,FX,-105480 F,172,FX,-3166.8 F,173,FX,-2002.8 F,174,FX,-2095.8 F,175,FX,-2245.2 F,176,FX,-2403 F,177,FX,-2514 F,178,FX,-2645.4 F,179,FX,-2842.2 F,180,FX,-2974.2 F,181,FX,-3084.6 F,182,FX,-3294 F,183,FX,-3457.8 F,184,FX,-3634.2 F,185,FX,-3837.6 F,186,FX,-3927.6 F,187,FX,-4107.6 F,188,FX,-4334.4 F,189,FX,-4444.2 F,190,FX,-4792.2 F,1,FY,49554 F,2,FY,68400 F,3,FY,-84060 F,9,FY,39192 F,10,FY,19410 F,11,FY,28320 F,12,FY,84660 F,13,FY,98160 F,14,FY,109020 F,19,FY,125820 F,20,FY,124500 F,21,FY,-86760 F,28,FY,116760 F,29,FY,121440 F,31,FY,124260 F,33,FY,126180 F,35,FY,127320 F,37,FY,127860 F,39,FY,127920 F,41,FY,127560 F,42,FY,126840 F,44,FY,122880 F,46,FY,120780 F,48,FY,118200 F,50,FY,114900 F,52,FY,110820 F,53,FY,96840 F,54,FY,105180 F,56,FY,85740 F,57,FY,72420 F,58,FY,56898 F,172,FY,-182820 F,173,FY,-177480 F,174,FY,-178140 F,175,FY,-178620 F,176,FY,-179040 F,177,FY,-179580 F,178,FY,-180240 F,179,FY,-180900 F,180,FY,-181500 F,181,FY,-182100 F,182,FY,-183480 F,183,FY,-184140 F,184,FY,-184860 F,185,FY,-185640 F,186,FY,-186480 F,187,FY,-187320 F,188,FY,-188100 F,189,FY,-189000

F,190,FY,-189900 ESEL,S,LIVE !选择具“生/SOLU !进入求解器 属性”的单元 /STATUS,SOLU PLDISP,1 !显示变形ALLS !选择所有内容 情况

SOLVE !求解计算 PLNSOL,U,X,0,1 !绘制水平方向位移云图 !求解 /SOLU !进入求解器 ANTYPE,,REST,2 !重新启动求解器 ESEL,S,,,172,350 !选择上台阶开

挖土体单元

EKILL,ALL !对所选单元赋予“死属性”

ESEL,S,,,5,8 !选择单元(上部开

挖区支护)

ESEL,A,,,1 !补选单元

ESEL,A,,,11,12 ESEL,A,,,16 ESEL,A,,,20,34,2 ESEL,A,,,35,49,2 ESEL,A,,,50 ESEL,A,,,52,53 ESEL,A,,,55,56 ESEL,A,,,59 ESEL,A,,,64,69 ESEL,A,,,73,75 ESEL,A,,,79,81 ESEL,A,,,85,150 ESEL,A,,,154,162 EALIVE,ALL !对所选单元赋予“生属性”

FINISH /SOLU !进入求解器

/STATUS,SOLU ALLS !选择所有

内容

SOLVE !进行求解

计算 save,tunnel-step2,db !把初

始应力模拟求解结果保存 /POST1 !进入后处理器 PLNSOL,U,Y,0,1 !绘制竖直方向位移云图 PLNSOL,S,X,0,1 !绘制水平方向应力云图 PLNSOL,S,Y,0,1 !绘制竖直方向应力云图 PLNSOL,S,1,0,1 !绘制第一主应力云图 PLNSOL,S,3,0,1 !绘制第三主应力云图

FINISH /POST1 !进入后处理器

ETABLE,IMFORX,SMISC, 1 ETABLE,JMFORX,SMISC, 7 ETABLE,IMFORY,SMISC,2 ETABLE,JMFORY,SMISC, 8 ETABLE,IMMOMZ,SMISC,6 ETABLE,JMMOMZ,SMISC,12 PLLS,IMFORX,JMFORX,0.2 !绘制上台阶开挖轴力图 PLLS,IMFORY,JMFORY,0.5 !绘制上台阶开挖剪力图 PLLS,IMMOMZ,JMMOMZ,-0.1 !绘制上台阶开挖弯矩图 ESEL,S,,,331,350 !选择单元 ESEL,A,,,456 !补选单元 ESEL,A,,,620,626,6 ESEL,A,,,459

ESEL,A,,,465,477,6 ESEL,A,,,480,588,6 ESEL,A,,,597

ESEL,A,,,600 ESEL,A,,,609

ESEL,A,,,615 ESEL,A,,,627 ESEL,A,,,621 NFORCE,ALL,ALL!提取所选单元的节点力

FINISH !进行隧道下台阶开挖 /SOLU !进入求解器 ANTYPE,,REST,3 !重新启动求解器 ESEL,S,,,172,350 !选择上台阶开

挖土体单元

EKILL,ALL !对所选单元赋予“死属性” ESEL,S,,,5,8 !选择单元(上部开挖区支护)

ESEL,A,,,1 !补选单元 ESEL,A,,,11,12 ESEL,A,,,16 ESEL,A,,,20,34,2 ESEL,A,,,35,49,2 ESEL,A,,,50 ESEL,A,,,52,53 ESEL,A,,,55,56 ESEL,A,,,59 ESEL,A,,,64,69 ESEL,A,,,73,75 ESEL,A,,,79,81 ESEL,A,,,85,150 ESEL,A,,,154,162

EALIVE,ALL !对所选单元赋予“生属性”

ESEL,S,,,351,449 !选择下台阶开挖土体单元

EKILL,ALL !对所选单元赋予“死属性”

ESEL,S,LIVE !选择具“生属性”的单元 FDELE,3,ALL !删除上下台阶分解处节点上所加的节点力 FDELE,21,ALL

FDELE,172,ALL,190 F,3,FX,-163860 F,4,FX,-139020 F,5,FX,-677.4 F,6,FX,-19.356 F,7,FX,22020 F,8,FX,66900 F,15,FX,-5695.2 F,16,FX,-4648.2 F,17,FX,3754.2 F,18,FX,1912.2 F,22,FX,-67080 F,23,FX,-104520 F,24,FX,-29340 F,25,FX,-9918 F,26,FX,-8268 F,27,FX,-7290 F,30,FX,-3839.4 F,32,FX,-2950.8 F,34,FX,-2502 F,36,FX,-1700.4 F,38,FX,-972.6 F,40,FX,-825.6 F,43,FX,558.12 F,45,FX,1156.2 F,47,FX,1553.4 F,49,FX,2032.8 F,51,FX,2641.2 F,55,FX,977.4 F,59,FX,102540 F,60,FX,153480 F,3,FY,-136740 F,4,FY,464.1 F,5,FY,-80760 F,6,FY,-82680 F,7,FY,-184980 F,8,FY,-97320 F,15,FY,-118320 F,16,FY,-105960 F,17,FY,-137280 F,18,FY,-161220 F,22,FY,-98880 F,23,FY,3067.2 F,24,FY,-172740 F,25,FY,-184500 F,26,FY,-155580 F,27,FY,-133860 F,30,FY,-96660 F,32,FY,-89880 F,34,FY,-85200 F,36,FY,-82020 F,38,FY,-80220 F,40,FY,-79800 F,43,FY,-86040 F,45,FY,-91080 F,47,FY,-98280 F,49,FY,-107940 F,51,FY,-120660 F,55,FY,-194280

F,59,FY,-15474 F,60,FY,40758

/SOLU !进入求解器 /STATUS,SOLU

ALLS !选择所有内容 SOLVE !进行求解计算

/SOLU !进入求解器 ANTYPE,,REST,4 !重新启动求解器 ESEL,S,,,172,350 !选择上台阶开挖土体单元

EKILL,ALL !对所选单元赋予“死属性”

ESEL,S,,,5,8 !选择单元(上部开挖区支护)

ESEL,A,,,1 !补选单元 ESEL,A,,,11,12 ESEL,A,,,16 ESEL,A,,,20,34,2 ESEL,A,,,35,49,2 ESEL,A,,,50 ESEL,A,,,52,53 ESEL,A,,,55,56 ESEL,A,,,59 ESEL,A,,,64,69 ESEL,A,,,73,75 ESEL,A,,,79,81 ESEL,A,,,85,150 ESEL,A,,,154,162

EALIVE,ALL !对所选单元赋予“生属性” ESEL,S,,,351,449 !选择下台阶开挖土体单元

EKILL,ALL !对所选单元赋予“死属性”

ESEL,S,,,2,4 !选择单元(下部开挖区支护) ESEL,A,,,9,10 !补选单元 ESEL,A,,,13,15 ESEL,A,,,17,19 ESEL,A,,,21,33,2

ESEL,A,,,36,48,2 ESEL,A,,,51 ESEL,A,,,54 ESEL,A,,,57,58 ESEL,A,,,60,63 ESEL,A,,,70,72 ESEL,A,,,76,78 ESEL,A,,,82,84 ESEL,A,,,151,153 ESEL,A,,,163,171

EALIVE,ALL !对所选单元赋予“生属性” FINISH

/SOLU !进入求解器 /STATUS,SOLU

ALLS !选择所有内容 SOLVE !进行求解计算

/POST1 !进入后处理器 ESEL,S,LIVE !选择具有“生属性”的单元 PLDISP,1 !显示变形情况 PLNSOL,U,X,0,1 !绘制水平方向位移云图 PLNSOL,U,Y,0,1 !绘制竖直方向位移云图 PLNSOL,S,X,0,1 !绘制水平方向应力云图 PLNSOL,S,Y,0,1 !绘制竖直方向应力云图 PLNSOL,S,1,0,1 !绘制第一主应力云图 PLNSOL,S,3,0,1 !绘制第三主应力云图 ETABLE,IMFORX,SMISC, 1 ETABLE,JMFORX,SMISC, 7 ETABLE,IMFORY,SMISC,2 ETABLE,JMFORY,SMISC, 8 ETABLE,IMMOMZ,SMISC,6 ETABLE,JMMOMZ,SMISC,12

PLLS,IMFORX,JMFORX,0.2 !绘制下台阶开挖后轴力图

PLLS,IMFORY,JMFORY,0.5 !绘制下台阶开挖后剪力图

PLLS,IMMOMZ,JMMOMZ,-0.1 !绘制下台阶开挖后弯矩图