锚杆喷射混凝土支护技术规范.docx
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锚杆喷射混凝土支护技术规范.docx
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锚杆喷射混凝土支护技术规范
锚杆喷射混凝土支护技术规范Specificationsforbolt-shotcretesupport
目次
1总则························································································································································12术语、符号················································································································································2
2.1术语·····················································································································································22.2符号·····················································································································································3
3围岩分级····················································································································································54锚喷支护设计·········································································································································10
4.1一般规定··············································································································································104.2锚杆支护设计······································································································································144.3喷射混凝土支护设计···························································································································174.4特殊条件下的锚喷支护设计················································································································194.5边坡锚喷支护设计·······························································································································22
5现场监控量测·······································································································································24
5.1一般规定··············································································································································245.2现场监控量测的内容与方法················································································································245.3现场监控量测的数据处理和反馈········································································································24
6光面爆破··················································································································································267锚杆施工··················································································································································28
7.1一般规定··············································································································································287.2全长粘结型锚杆施工···························································································································287.3端头锚固型锚杆施工···························································································································297.4摩擦型锚杆施工···································································································································297.5预应力锚杆施工···································································································································297.6预应力锚杆的试验和监测···················································································································307.7自钻式锚杆的施工·······························································································································32
8喷射混凝土施工·····································································································································33
8.1原材料··················································································································································338.2施工机具··············································································································································338.3混合料的配合比与拌制·······················································································································348.4喷射前的准备工作·······························································································································348.5喷射作业··············································································································································348.6钢纤维喷射混凝土施工·······················································································································368.7钢筋网喷射混凝土施工·······················································································································368.8钢架喷射混凝土施工···························································································································368.9水泥裹砂喷射混凝土施工···················································································································378.10喷射混凝土强度质量的控制··············································································································37
9安全技术与防尘·····································································································································39
9.1安全技术··············································································································································399.2防尘······················································································································································40
10质量检查与工程验收··························································································································41
10.1质量检查············································································································································4110.2工程验收············································································································································43
附录A喷射混凝土与围岩粘结强度试验·····························································································45
附录B现场监控量测记录表··················································································································47附录C锚杆基本试验循环加缷荷等级与位移观测间隔时间表······················································48附录D喷锚混凝土强度质量··················································································································49附录E测定喷射混凝土粉尘的技术要求·····························································································50附录F喷射混凝土抗压强度标准试块制作方法················································································51附录G喷锚支护施工记录·······················································································································52本规范用词说明···········································································································································54条文说明························································································································································55
1总则
1.0.1为使锚杆喷射混凝土支护简称锚喷支护工程的设计施工符合技术先进、经济合理、安全适用、确保质量的要求,特制定本规范。
1.0.2本规范适用于矿山井巷、交通隧道、水工隧洞和各类洞室等地下工程锚喷支护的设计与施工。
也适用于各类岩土边坡锚喷支护的施工。
1.0.3锚喷支护的设计与施工,必须做好工程的地质勘察工作,因地制宜,正确有效地加固围岩,合理利用围岩的自承能力。
1.0.4锚喷支护的设计与施工,除应遵守本规范外,尚应符合现行国家标准的有关规定。
1
2术语、符号
2.1术语
2.1.1初期支护initialsupport
当设计要求隧洞的永久支护分期完成时,隧洞开挖后及时施工的支护,称为初期支护.
2.1.2后期支护Finalsupport
隧洞初期支护完成后,经过一段时间,当围岩基本稳定,即隧洞周边相对位移和位移速度达到规定要求时,最后施工的支护,称为后期支护。
2.1.3拱腰haunch
隧洞拱顶至拱脚弧长的中点称为拱腰。
2.1.4隧洞周边位移convergenceoftunnelinnerperimeter
隧洞周边相对应两点间距离的变化,称为隧洞周边位移。
2.1.5锚固力anchoringforce
锚杆对围岩所产生的约束力,称为锚固力。
2.1.6抗拔力anti-pullforce
阻止锚杆从岩体中拔出的力,称为抗拔力。
2.1.7润周wettedperimeter
水土隧洞过水断面的周长,称为润周。
2.1.8点荷载强度指数point-loadingstrengthindex
直径50mm圆柱形标准试件径向加压时的点荷载强度。
2.1.9系统锚杆systembolt
为使围岩整体稳定,在隧洞周边上按一定格式布置的锚杆群,称为系统锚杆。
2.1.10预应力锚杆prestressanchor
由锚头、预应力筋、锚固体组成,利用预应力筋自由段(张拉段)的弹性伸长,对锚杆施加预应力,以提供所需的主动支护拉力的长锚杆。
本规范所指的预应力锚杆系指预应力值大于200kN、长度大于8.0m的锚杆。
2.1.11缝管锚杆splitset
将纵向开缝的薄壁钢管强行推入比其外径较小的钻孔中,借助钢管对孔壁的径向压力而起到摩擦锚固作用的锚杆。
2.1.12水胀锚杆swellexbolt
将用薄壁钢管加工成的异形空腔杆体送入钻孔中,通过向该杆件空腔高压注水,使其膨胀并与孔壁产生的摩擦力而起到锚固作用的锚杆。
2.1.13自钻式锚杆self-drillingbolt
将钻孔、注浆与锚固合为一体,中空钻杆即作为杆体的锚杆。
2.1.14喷射混凝土shotcrete
2
利用压缩空气或其他动力,将按一定配比拌制的混凝土混合物沿管路输送至喷头处,以较高速度垂直喷射于受喷面,依赖喷射过程中水泥与骨料的连续撞击,压密而形成的一种混凝土。
2.1.15水泥裹砂喷射混凝土sendenvelopedbycement(SEC)shotcrete
将按一定配比拌制而成的水泥裹砂砂浆和以粗骨料为主的混合料,分别用砂浆泵和喷射机输送至喷嘴附近相混合后,高速喷到受喷面上所形成的混凝土。
2.1.16格栅钢架reinforcing-bartruss
用钢筋焊接加工而成的桁架式支架。
2.2符号
2.2.1抗力和材料性能
2.2.2作用和作用效应
3
2.2.3几何参数
2.2.4计算系数
4
3围岩分级
3.0.1锚喷支护工程的地质勘察工作应为围岩分级提供依据,并应贯穿工程建设始终。
3.0.2围岩级别的划分,应根据岩石坚硬性、岩体完整性、结构面特征、地下水和地应力状况等因素综合确定。
并应符合表3.0.2的规定。
3.0.3岩体完整性指标用岩体完整性系数表示可按下式计算:
⎛VpmKv=V⎝pr⎫(3.0.3)⎪⎪⎭2
式中Vpm—隧洞岩体实测的纵波速度(km/s)
Vpr—隧洞岩石实测的纵波速度(km/s)
当无条件进行声波实测时,也可用岩体体积节理数Jv,按表3.0.3确定Kv值。
表3.0.3Jv与Kv对照表
1当有地应力实测数据时:
Sm=Kvfr
σ1(3.0.4-1)
式中Sm—岩体强度应力比;
fr—岩石单轴饱和抗压强度(MPa);
Kv—岩体完整系数;
。
σ1—垂直洞轴线的较大主应力(KN/㎡)
2当无地应力实测数据时:
σ1=γH(3.0.4-2)
式中γ——岩体重力密度(KN/m³);
H——隧洞顶覆盖层厚度(m)。
3.0.5对Ⅲ、Ⅳ级围岩,当地下水发育时,应根据地下水类型、水量大小、软弱结构面多少及其危害程度,适当降级。
3.0.6对于Ⅱ、Ⅲ、Ⅳ级围岩,当洞轴线与主要断层或软弱夹层的夹角小于30°时,应降一级。
5
表3.0.2围岩分级
6
续表3.0.2
7
8
9
4锚喷支护设计
4.1一般规定
4.1.1锚喷支护的设计,宜采用工程类比法,必要时应结合监控量测法及理论验算法。
4.1.2锚喷支护初步设计阶段,应根据地质勘察资料,按本规范表3.0.2的规定,初步确定围岩级别,并按表4.1.2-1和表4.1.2-2的规定,初步选择隧洞、斜井或竖井的锚喷支护类型和设计参数。
4.1.3锚喷支护施工设计阶段,应做好工程的地质调查工作,绘制地质素描图或展示图,并标明不稳定块体的大小及其出露位置。
实测围岩分级定测指标,按本规范3.0.2的规定,详细划分围岩级别,并修正初步设计。
4.1.4对Ⅳ、Ⅴ级围岩中毛洞跨度大于5m的工程,除应按照本规范表4.1.2-1的规定,选择初步支护的类型与参数外,尚应进行监控量测,以最终确定支护类型和参数。
4.1.5对Ⅰ、Ⅱ、Ⅲ级围岩毛洞跨度大于15m的工程,除应按照本规范表4.1.2-1的规定,选择支护的类型与参数外,尚应对围岩进行稳定性分析和验算;对Ⅲ级围岩,还应进行监控量测,以最终确定支护类型和参数。
4.1.6对围岩整体稳定性验算,可采用数值解法或解析解法;对局部可能失稳的围岩块体的稳定性验算,可采用块体极限平衡方法。
4.1.7对边坡工程喷锚支护设计,应充分掌握工程的地质勘察资料,按不同的失稳破坏类型,采用极限平衡法、数值分析法等方法进行边坡稳
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