地铁隧道施工外文文献翻译

(含：英文原文及中文译文)
文献出处：Cocheril Y. Study on Construction Technology of Multi-Arch Tunnel Group in Urban Underground Railway[J]. Journal of Communications, 2015, 3(4):22-32.
英文原文
Study on Construction Technology of Multi-Arch Tunnel Group in Urban
Underground Railway
Y Cocheril
Abstract
In this paper, the construction method of the multi-arch tunnel group is discussed by using an engineering example of Metro Line 3. In the construction of the subway, the construction technique of changing a multi-arch tunnel into a single-hole tunnel was first proposed. The technical solutions of the single-middle wall and the separated middle-wall structure were compared and selected to meet the requirements of structural safety, construction safety, and economic efficiency. Good technical solutions can provide reference and reference for the design and construction of similar projects in the future. Keywords: multi-arch tunnel group, single middle partition wall, separated middle partition wall, construction technology
Because of the design requirements of the subway tunnel, a variety
of tunnel structures are required. Among them, a multi-arch tunnel segment consisting of unequal cross-linked arches and triple-arched tunnels is often used for the connection of the main line and the crossover line. This article combines the project example according to the geological conditions of the tunnel, the time limit requirements through comparison and selection of the best construction program that can achieve rapid construction and save construction costs.
1 Project Overview
The return line of Sports West Road Station on Metro Line 3 is a complex type of return line from Sports West Road Station. In the section DK3016.047037.157, a tunnel group with unequal spans with double arches and triple arches was set up. Unequal cross-arch tunnel excavation span of 20.1m excavation height of 10.076m cross-vector ratio of 1:0.5 hole lining after the lining of 5.2m large-hole lining after the span of 11.4m in the wall thickness of 1.6m. The triple-arch tunnel excavation span is 19.9m and the 7.885m cross-vector ratio is 1:0.1. The surrounding rock of the section of the multi-arch tunnel is from top to bottom: artificial backfill, red sand and alluvial sand layer, alluvial-diluvial earth, fluvial-lacustrine sedimentary soil, plastic residual soil, hard plastic-hard residue. Soil, weathered rock formations, strong weathered rock formations, weathered layers, and weathered layers. Tunnels through the formation of more homogeneous rock strength, strong bearing capacity
and stability. The thickness of the vault covering the tunnel is 15.518m, and the thickness of the surrounding rock layer IV is 5.67.6m. The buried depth of groundwater in the section of the multi-arch tunnel is 2.284.1m, mainly Quaternary pore water and fissure water.
2 double arch construction plan
Due to the complex structure of the multi-arch tunnel section, the tunnel section changes greatly. The construction process is complex and the construction is difficult. The construction period is long. Therefore, it is very important to choose a good construction scheme to complete the construction of the multi-arch tunnel section with high quality and efficiency. When selecting a construction plan, the following aspects are mainly considered: 1 Construction safety and construction Safety 2 Construction difficulty 3 Construction cycle 4 Economic benefits. Based on these four principles, the following two construction plans were selected for comparative selection through the research and demonstration of the construction plan.
2.1 Single Wall Construction Plan
The main construction steps and measures of this program are as follows: 1 Prevent the construction of the middle wall from timely construction after the completion of the construction of the temporary construction channel, double-arched and triple-arched intermediate wall from the double-arched tunnel on the right line to the return line side. . 2
After the construction of the middle wall lining is completed, the CRD construction method for the right line shall be used for the construction of the large-span tunnel of the re-entry line in accordance with the principle of “small first, large, and closed”. (3) When the construction of the triple-arch tunnel on the side of the re-entry line is carried out, the construction of the triple-arch and double-arched middle wall shall be carried out in accordance with the construction method of the middle-wall of the right line. After the completion of the construction of the four-fold line on the side of the middle wall, the construction of the right line will continue. This construction method is applied to the general construction methods of domestic double-arch tunnels in Guangzhou Metro, Nanjing Metro and Beijing Subway, and can safely and smoothly complete the construction of tunnel groups. However, the study of previous engineering examples and construction techniques can reveal that the program still has shortcomings and defects. 1 This scheme is applied frequently in this project. The initial support and the secondary lining of the tunnel within the short 21.11m multi-arch tunnel will convert 4 times.
2 The waterproof layer construction, reinforcement engineering, formwork engineering, and concrete pouring involved in the lining of the middle wall and side tunnels all require multiple conversions and a construction period of up to 2 months. After the completion of the lining, the investment of the anti-bias support of the middle wall and the
equipment and equipment will lead to higher construction costs and lower economic benefits.
2.2 Separated Wall Construction Plan
The main construction steps and measures of this plan are as follows: 1 Change the unequal span double-arch tunnels into two single holes to change the separation-type mid-rise wall first from the right-line single-line tunnel construction. 2 Double-arched tunnels will not be used for middle-liner lining under single-line conditions. 3 The right-sided large-section double-arch tunnel passes through the side wall of the CRD method. For the 4 fold back line, the construction is performed in the reverse order of the right line. Adopting this scheme is actually a comparison between the two single-line construction methods and the previous one. This has the following advantages: 1 Reduce the number of construction processes and speed up the transition of the process. 2 Reduced the difficulty of construction and shortened the construction period. 3 Reduced construction costs and increased economic efficiency.
4 The change to a single wall in the middle of the wall has completely solved the waterproofing defects of the double-arch tunnel structure.
5 The construction of the middle tunnel of a triple-arch tunnel is equivalent to a large-span tunnel with reserved core rock, which is conducive to the construction of safety double-arch tunnels on both sides.
3 Three Arches Construction Plan
From the right line directly into the triple-arch tunnel, its supporting parameters are based on the original design, and the entire ring is installed. The whole ring is sprayed on the design and the anchor bar at the middle wall is reinforced. The re-entry side is the same as the right-line construction method. It is necessary to remove a longitudinal reinforcement beam at the junction of the tunnel grille. Strictly control the distance between each step of the excavation footage grid is 0.6m/榀. The middle-wall excavation adopts a weak-weak-weakening blasting scheme to conditionally use the static blasting scheme to minimize the disturbance to the middle-wall rock formation and the lining tunnel to ensure construction safety. The secondary lining is performed immediately after the middle wall excavation is completed. After the completion of the construction of the middle wall, the gaps in the middle walls will be backfilled with jack support. Only one side of the construction is completed before the other side of the wall construction. After the completion of the construction of the middle walls on both sides, the secondary lining of the single-hole tunnels on both sides shall be promptly conducted, and then the excavation and lining of the middle rock mass of the triple-arch tunnel shall be carried out. Special attention should be paid to the settlement and convergence deformation of the triple-arch tunnel at the middle of construction.
4 Analysis of structural behavior during construction
Changed the cancellation of mid-walls that do not cross double arches into separated walls. There is no similar engineering design and construction experience in domestic urban subway projects, and there is no similar tunnel structure design. Therefore, whether the structure is safe and whether the construction process is changed during the construction process. Safety will be the focus of this program. Using ANSYS finite element general program software to perform numerical simulations on unequal cross-arch tunnels. The strata-structure model was used to analyze the stress and deformation of the tunnel structure (Fig. 1, Fig. 2, Fig. 3). The horizontal direction of the force taken along the direction of the tunnel is limited to 3 times the hole span. The vertical direction is taken upwards to the surface, and the bottom is 3 times the hole span. Element model Elasto-plastic physical tunnel lining with DP stratum material adopts elasticity The beam element simulation beam elements and solid elements are connected using a coupling equation. It can be seen from the data analysis in Table 2 that the large tunnel has a greater impact on the small tunnel during construction. If the necessary reinforcement measures are taken for the small section tunnel and the longitudinal demolition distance of the temporary support is controlled, this scheme is beneficial and feasible.
5 Key Construction Technologies and Corresponding Measures
The construction of the multi-arch tunnel section needs to be carried
out under strict construction organization and strong technical guarantee measures. The construction of each construction step is a key to successful construction.
5.1 Pulling bolts and reinforcing bolts
After the removal of the single middle wall, the thickness of the middle wall after the excavation is completed is 0.8m. It is very necessary to set the anchor bolt and the reinforcement bolt. For the tension bolt, the length of the Φ22 steel reel bolt i s 0.6m2150.5m, and the thickness of the middle wall is 0.82.0m. Reinforced anchor rods are installed at the inverting arch and side wall at both sides of the middle wall with a Φ25 hollow grouting anchor spacing of 0.6m21.50.8m.
5.2 Grouting Reinforcement in Middle Wall Rock Pillar
The thinnest part of the rock mass in the middle wall is 0.15m. After several blasting excavation processes, the surrounding rock around the middle wall loosens its bearing capacity. Therefore, the loose surrounding rock must be grouted in the vaults, walls and inverted arches of the middle wall. The embedded Φ42 steel pipe slurry adopts a cement-water glass double slurry parameter of 1:1 cement slurry and 3045Be. In the two excavations, the grouting pressure of the inflow glass solution of the middle wall is 0.21.0 MPa. After the final excavation of the grouting line,
a saturated grouting is performed on the sandwich wall.
5.3 Differential Blasting Technology
All the tunnel excavations are drilled and blasted. Because the ground buildings in the downtown area of Guangzhou City are dense and the tunnel is blasted at a distance of “0”, the blasting vibration must be controlled within the allowable range in accordance with the blasting scheme for micro-shock blasting in the reserved smooth layer. The blasting measures taken for Grade III and Grade IV surrounding rocks in the strata of a multi-arch tunnel are as follows: (1) Blasting equipment uses emulsion explosives with low seismic velocity. 2 Strictly control the distance between the perforation of 0.60.8m per cycle and the distance between the peripheral blastholes of 0.4m to reduce the charge volume and control the smooth blasting effect. 3 Multi-stage detonator detonation in each blasting The non-electrical millimeter detonator is used to asymmetrically detonate the network micro-vibration technology. 4Second excavation is adopted at the middle wall. 1m is reserved for the smooth surface. Grooves are arranged on the side far away from the middle wall. medicine. The use of artificial wind excavation for excavation of partially dug excavation is prohibited. Through the above-mentioned effective measures, the “0” distance excavation of the multi-arch tunnel was smoothly passed without causing damage to the 0.15-m thick middle wall during the secondary blasting of the middle wall.
5.4 Assisted Scissor Support
Through ANSYS simulation analysis In order to ensure the safety of small-section tunnel construction, it is necessary to assist the reinforcement of the small-section tunnel to withstand the transient impact caused by blasting and the bias generated by the load release during excavation of the rock formation. The support material is welded to both ends of the grid pre-embedded steel plate with I20 steel and the spacing of the support arrangement is 0.6m, ie high strength bolts are used on each grid. The layout of the arrangement was extended to 1.2m on each side of the double arch and completed in front of the big end of the excavation. The height and angle of the support arrangement should ensure smooth construction machinery and equipment. Through the construction proof that the setting of the support is necessary and effective, the small section tunnel converges only 5 mm after the auxiliary scissor is added.
5.5 Information Construction
In order to ensure structural safety and construction safety, real-time monitoring measurement is carried out during the tunnel construction process. The deformation characteristics of supporting structures and surrounding strata are used to predict the corresponding support structure displacements and to verify the rationality of supporting structures to provide a basis for information construction. Monitoring during construction shows that the maximum settlement of a tunnel with a small
cross section is 14.6 mm. The maximum settlement of a tunnel with a large section is 17.2 mm. The maximum convergence of the tunnel is 7.6 mm. The maximum settlement of the ground is 10 mm. The maximum settlement of the arch with a triple hole arch is 22.8 mm.
中文译文
城市地下铁道连拱隧道群施工技术研究
作者Y Cocheril
摘要
本文利用地铁三号线某一工程实例对连拱隧道群施工工法进行探讨。

在地铁施工中首次提出了将连拱隧道改为单洞隧道施工技术并对单一式中墙和分离式中墙结构的技术方案进行了比选得出了满足结构安全、施工安全和经济效益较好的技术方案可为今后类似工程的设计和施工提供借鉴和参考。

关键词：连拱隧道群，单一式中隔墙，分离式中隔墙，施工技术地铁隧道由于线路设计要求产生多种隧道结构形式其中由不等跨双连拱和三连拱隧道组成的连拱隧道段常用于正线和渡线的连接。

本文结合工程实例根据隧道所处地质条件、工期要求通过比选提出了可达到快速施工和节省施工成本目的的最佳施工方案。

1 工程概况
地铁三号线体育西路站折返线为体育西路站站后折返线结构形式复杂在DK3016.047037.157 段设置了不等跨双连拱结构、三连拱
结构等隧道群。

不等跨连拱隧道开挖跨度为20.1m开挖高度为
10.076m跨矢比为1∶0.5小洞衬砌后跨度为5.2m大洞衬砌后跨度为
11.4m中墙厚度为1.6m。

三连拱隧道开挖跨度为19.9m开挖高度为7.885m跨矢比为1∶0.1。

连拱隧道段的围岩自上而下有:人工填土层、冲-洪积砂层、冲积-洪积土层、河湖相沉积土层、可塑状残积土、硬塑-坚硬状残积土、全风化岩层、强风化岩层、中风化层和微风化层。

隧道通过地层岩质较为均一强度较高承载能力强稳定性好。

隧道拱顶覆盖层厚度为15.518m其中拱顶Ⅳ级围岩层厚度为5.67.6m。

连拱隧道段地下水埋深为2.284.1m主要是第四系孔隙水和裂隙水。

2 双连拱段施工方案
由于连拱隧道段结构比较复杂隧道断面变化较大施工工序繁复施工难度高施工周期长所以选择一个好的施工方案对优质高效完成连拱隧道段的施工尤为重要。

选择施工方案时主要考虑以下几个方面:1 施工安全和结构安全2施工难度3施工周期4经济效益。

本着这四条原则经过施工方案的研究和论证选出下面两个施工方案进行比较甄选。

2.1 单一式中墙施工方案
该方案的主要施工步骤及措施如下: 1从右线双连拱小洞隧道内向折返线侧进行临时施工通道、双连拱和三连拱中墙施工完成后中墙及时支撑施工时防止偏压。

2中墙衬砌施工完成后按照“先小后大、封闭成环”的原则用台阶法进行右线施工用CRD 工法进行折返线大跨度隧道施工。

3当折返线侧施工到三连拱隧道中墙后再按照右线
中墙施工方法进行三连拱和双连拱中墙施工这期间右线停止掘进直到中墙施工完成。

4折返线侧中墙施工完成后右线继续往前施工。

该工法为国内连拱隧道常规施工工法广州地铁、南京地铁和北京地铁中均有应用并能安全顺利地完成隧道群的施工。

但是对以往的工程实例和施工技术的研究可以发现该方案还存在不足和缺陷。

1本方案运用于本工程上在短短的21.11m 的连拱隧道内隧道的初期支护和二次衬砌间将转换4 次转换过于频繁。

2中墙和边洞隧道衬砌涉及的防水层施工、钢筋工程、模板工程、混凝土浇注均需多次转换施工周期长达2个月。

3衬砌完成后中墙防偏压支撑和材料设备的投入导致施工成本增高经济效益降低。

2.2 分离式中墙施工方案
该方案的主要施工步骤及措施如下: 1将不等跨双连拱隧道改为两个单洞变更为分离式中墙先从右线单线隧道往前施工。

2对三连拱隧道先不施作中墙衬砌按单线工况通过。

3对右线的大断面双连拱隧道按照CRD 工法侧壁通过。

4折返线侧则按照右线相反的施工顺序进行施工。

采用本方案实际就是按照两条单线的施工方法进行与上一方案进行对比后具有如下优点: 1减少施工工序加快工序的衔接转换。

2降低了施工难度缩短了施工周期。

3降低了施工成本提高了经济效益。

4变单一式中墙为分离式中墙彻底地解决了连拱隧道结构的防水上的缺陷。

5三连拱隧道中洞后期施工相当于大跨度隧道预留了核心岩体有利于两侧双连拱隧道施工安全表。

3 三连拱段施工方案
从右线直接进入三连拱隧道其支护参数以原设计进行格栅全环安设按设计全环喷射混凝土并加强中墙拱顶处的锚杆设置折返侧同右线施工方法在中墙施工时需要破除隧道格栅接头处设一纵向加强梁。

严格控制每循环开挖进尺格栅间距为0.6m/榀。

中墙开挖采用微差弱爆破方案有条件尽量采用静态爆破方案最大限度地减少对中墙岩层和已衬砌隧道的扰动确保施工安全。

中墙开挖完成后立即进行二次衬砌。

中墙施工完成后对中墙空隙进行回填加千斤顶支护。

一侧施工完成后才进行另一侧中墙施工。

当两侧中墙施工完成后及时进行两侧单洞隧道的二次衬砌然后进行三连拱隧道中间岩体的开挖和衬砌。

施工中应特别注意三连拱隧道中墙处的沉降和收敛变形如出现异常现象立即进行加固处理。

4 施工时结构受力性态分析
将不等跨双连拱的中墙取消改为分离式中墙在国内城市地下铁道工程中尚未有类似工程设计及施工经验也没有类似隧道结构设计因此结构是否安全以及施工过程中工序转换时施工是否安全将是本方案研究的重点。

应用ANSYS 有限元通用程序软件对不等跨连拱隧道进行数值模拟计算采用地层-结构的模式对隧道结构的受力和变形进行分析图1、图2、图3。

所取受力范围水平方向沿隧道横断面方向以洞跨的 3 倍为限垂直方向上方取至地表、下方以洞跨的 3 倍为限单元模型采用DP 地层材料的弹塑性实体隧道衬砌采用弹性梁单元模拟梁单元和实体单元采用藕合方程连接。

通过表 2 中的数据分析可以看出大隧道在施工时对小隧道的影响较大如果对小断面
隧道采用必要的加强措施并控制临时支撑的纵向拆除间距该方案是有益并可行的。

5 施工关键技术及对应措施
连拱隧道段的施工是需要在严密的施工组织和强有力的技术保证措施下进行的组织好各施工步骤准备好各种技术预防措施是施工成功的关键。

5.1 对拉锚杆及加强锚杆
取消单一式中墙后开挖完成后中墙厚度为0.8m对拉锚杆和加强锚杆的设置是非常必要的。

对拉锚杆采用Φ22 钢筋药卷锚杆间距为0.6m2150.5m长度根据中墙的厚度变化为0.82.0m。

加强锚杆设于中墙两侧仰拱和边墙处采用 3.0m 的Φ25 中空注浆锚杆间距0.6m2150.8m。

5.2 中墙夹岩柱体注浆加固
中墙岩体最薄处为0.15m经过多次爆破开挖过程的影响中墙周围的围岩松动其承载力受影响。

因此必须分别在中墙拱顶、墙、仰拱处对松动围岩进行注浆。

预埋Φ42 钢管浆液采取水泥-水玻璃双液浆参数为1∶1 水泥浆和3045Be 在两次开挖中中墙均进水玻璃溶液注浆压力为0.21.0MPa。

行注浆最后开挖完成后对中墙夹层进行饱和注浆。

5.3 微差微震爆破技术
隧道开挖全部采用钻爆法施工。

由于地处广州市繁华地段地面建筑物密集且隧道采用“0”间距开挖爆破时必须按照预留光面层光面微
震微差爆破方案进行施工将爆破震动控制在容许范围内。

对于连拱隧道所处地层为Ⅲ、Ⅳ级围岩采取的爆破措施为: 1爆破器材采用低震速乳化炸药。

2严格控制每循环进尺0.60.8m周边炮眼间距为0.4m 减少装药量控制光面爆破效果图4。

3每次爆破使用多段位雷管起爆采用非电毫秒雷管不对称起爆网路微震动技术。

4中墙处采取二次开挖施工先预留1m 光面层掏槽眼布置在远离中墙的一侧对预留的光面层二次爆破时周边眼光面层多布置空眼、少装药。

杜绝超挖局部欠挖时采用人工风镐开挖。

通过以上有效措施在中墙二次爆破施工时对0.15m 厚的中墙基本未造成破坏顺利通过了连拱隧道的“0”距离开挖。

5.4 辅助剪刀撑加强支护
通过ANSYS 模拟分析为确保小断面隧道施工安全必须对小断面隧道进行辅助支撑加固抵御爆破产生的瞬时冲击和岩层开挖时荷载释放产生的偏压。

支撑材料采用I20 型钢焊接于两端格栅预埋钢板上并支撑布置间距为0.6m即每一榀格栅上均采用高强螺栓加固。

布置布置范围延长至双连拱两边各1.2m并在开挖大端面前完成。

支撑布置的高度和角度要确保施工机械设备能顺利通行。

通过施工证明支撑的设置是必要和有效的小断面隧道在加设辅助剪刀撑后收敛仅为5mm。

5.5 信息化施工
为确保结构安全和施工安全在隧道施工过程中开展实时监控量测研究支护结构和周边地层的变形特征预测相应的支护结构变位并
验证支护结构的合理性为信息化施工提供依据。

施工中监控量测显示小断面隧道最大沉降为14.6mm大断面隧道最大沉降为17.2mm结构收敛最大值为7.6mm地面最大沉降为10mm三连拱中洞开挖拱顶最大沉降为22.8mm。