隧道施工测量是隧道施工过程中不可缺少的一环，这项工作进行的好坏，直接影

隧道施工测量是隧道施工过程中不可缺少的一环，这项工作进行的好坏，直接影响到隧道能否按规定精度贯通和施工放样的准确程度。<br>（1） 洞外控制测量<br>我公司在进场和交接桩以后，组织测量技术力量对设计单位提供的平面控制网和高程控制网进行复测，洞口点准确设置。外业工作完成以后，对观测数据进行初步处理，并按要求进行平差计算和进洞关系计算，然后报监理工程师批准后使用，以确保隧道的施工精度。<br>（2） 洞内控制测量<br>洞内平面控制测量主要采用导线测量。由于隧道很短，洞内不考虑设置导线点，放样使用的置镜点每50m设置一个。<br>①、洞内平面控制点的选点、埋石<br>洞内控制点应选在通视良好，顶板或底板岩石坚固的地方，以使工作安全和控制点便于保存。洞内导线点兼作水准点使用，埋石方法、要求与洞外导线点相同。由于洞内施工和运输特别繁忙，光线较差，露出地面的标志易被破坏，导线点选择在中线的一侧，标石顶面应埋入地下10~20cm处，以坚固稳定、便于利用为原则，上面盖上铁板或厚木板，并注意不要压在金属标志上。埋石后，在边墙上以红油漆作为标志，标明点号、里程等，并以箭头指明埋点位置。<br>②、洞内导线测量<br>洞穴中的导线测量全部由全站仪执行。 测量方法与洞穴外的测量方法相同。 但是，由于洞穴中严峻的测量条件，为了减少折射误差的影响，应选择在较凉的夜晚和阴天进行测量。 目标必须与目标严格对齐。同时，可以使用两次瞄准和两次读数的方法，仪器衰减，the校准居中，以及瞄准读数误差。<br>③、洞内高程控制测量<br>A、洞内水准测量精度<br>地面与地下控制测量对贯通误差的影响，采取等影响分配原则，公路隧道的贯通限差为70mm，其中误差为35mm，则洞内高程贯通中误差为mh=0.71×35=24.8mm，由于水准线路小于5Km，采用等外水准测量即满足精度要求。<br>B、洞内水准测量施测<br>a、洞内水准测量利用平面控制点、主要导线点设置为永久水准点，施工导线点设置为临时水准点。<br>b、洞内水准点在隧道未贯通之前，只能布设支水准线路，为增加检核条件必须进行多次观测和往返观测。<br>c、随着隧道的掘进和水准点的延长，为满足施工放样和贯通精度的要求，先设置较低精度的水准点在施工导线点上，然后设置精度较高的水准点在主要导线点上。<br>d、由于洞内通视条件差，仪器到水准尺的距离不应超过50m。<br>C、洞内测距三角高程测量<br>洞内测距三角高程测量在全站仪导线测量时一并完成，即导线水平角测量，导线边长测量和导线高差测量一并完成。为了减少测量误差积累，导线点高程的传递通过主导线进行，施工导线点高程则由其附近的主导线点对其观测求得。<br>④、洞内中线测设<br>在隧道开挖初期，以洞口控制点为依据，放样临时隧道中线，指导隧道的开挖方向。当隧道掘进到一定距离，洞内控制点逐步建立以后，再测设正式中线点指导隧道的衬砌施工。由于隧道位于平曲线上，临时中线点每5-10m设一点；正式中线点每50m设一点。中线的测设可用极坐标法进行，为防止错误和提高精度，应以分中法测设中桩桩位。<br>⑤、洞内其它结构物的测设<br>洞内水平横洞、排水沟及其它结构物的测量放样，可根据这些结构物与中线的相对位置和设计高程进行测设。<br>（3）隧道贯通误差的测定与调整<br>当隧道相向开挖到贯通面时，由于受到测角、量距、水准测量等误差的联合影响，线路在中线与高程两方面均会产生实际贯通误差。为了保证线路中线平顺、断面尺寸与衬砌准确以及行车安全，必须进行贯通误差调整。<br>① 、隧道贯通误差的测定<br>在隧道贯通面任取一临时点E，分别由相向的两条导线附近的控制点测定该点的坐标，得两组坐标值（XE1，YE1），（XE2，YE2），由两边水准点测定E点高程为HE1，HE2。由此△S=[（XE2-XE1）2+（YE2-YE1）2]1/2即为平面实际贯通误差。

隧道施工测量是隧道施工过程中不可缺少的一环，这项工作进行的好坏，直接影响到隧道能否按规定精度贯通和施工放样的准确程度。<br>（1） 洞外控制测量<br>我公司在进场和交接桩以后，组织测量技术力量对设计单位提供的平面控制网和高程控制网进行复测，洞口点准确设置。 外业工作完成以后，对观测数据进行初步处理，并按要求进行平差计算和进洞关系计算，然后报监理工程师批准后使用，以确保隧道的施工精度。<br>（2） 洞内控制测量<br>洞内平面控制测量主要采用导线测量。 由于隧道很短，洞内不考虑设置导线点，放样使用的置镜点每50m设置一个。<br>①、洞内平面控制点的选点、埋石<br>洞内控制点应选在通视良好，顶板或底板岩石坚固的地方，以使工作安全和控制点便于保存。 洞内导线点兼作水准点使用，埋石方法、要求与洞外导线点相同。 由于洞内施工和运输特别繁忙，光线较差，露出地面的标志易被破坏，导线点选择在中线的一侧，标石顶面应埋入地下10~20cm处，以坚固稳定、便于利用为原则，上面盖上铁板或厚木板，并注意不要压在金属标志上。 埋石后，在边墙上以红油漆作为标志，标明点号、里程等，并以箭头指明埋点位置。<br>②、洞内导线测量<br>洞穴中的导线测量全部由全站仪执行。 测量方法与洞穴外的测量方法相同。 但是，由于洞穴中严峻的测量条件，为了减少折射误差的影响，应选择在较凉的夜晚和阴天进行测量。 目标必须与目标严格对齐。 同时，可以使用两次瞄准和两次读数的方法，仪器衰减，the校准居中，以及瞄准读数误差。<br>③、洞内高程控制测量<br>A、洞内水准测量精度<br>地面与地下控制测量对贯通误差的影响，采取等影响分配原则，公路隧道的贯通限差为70mm，其中误差为35mm，则洞内高程贯通中误差为mh=0.71×35=24.8mm，由于水准线路小于5Km，采用等外水准测量即满足精度要求。<br>B、洞内水准测量施测<br>a、洞内水准测量利用平面控制点、主要导线点设置为永久水准点，施工导线点设置为临时水准点。<br>b、洞内水准点在隧道未贯通之前，只能布设支水准线路，为增加检核条件必须进行多次观测和往返观测。<br>c、随着隧道的掘进和水准点的延长，为满足施工放样和贯通精度的要求，先设置较低精度的水准点在施工导线点上，然后设置精度较高的水准点在主要导线点上。<br>d、由于洞内通视条件差，仪器到水准尺的距离不应超过50m。<br>C、洞内测距三角高程测量<br>洞内测距三角高程测量在全站仪导线测量时一并完成，即导线水平角测量，导线边长测量和导线高差测量一并完成。 为了减少测量误差积累，导线点高程的传递通过主导线进行，施工导线点高程则由其附近的主导线点对其观测求得。<br>④、洞内中线测设<br>在隧道开挖初期，以洞口控制点为依据，放样临时隧道中线，指导隧道的开挖方向。 当隧道掘进到一定距离，洞内控制点逐步建立以后，再测设正式中线点指导隧道的衬砌施工。 由于隧道位于平曲线上，临时中线点每5-10m设一点；正式中线点每50m设一点。 中线的测设可用极坐标法进行，为防止错误和提高精度，应以分中法测设中桩桩位。<br>⑤、洞内其它结构物的测设<br>洞内水平横洞、排水沟及其它结构物的测量放样，可根据这些结构物与中线的相对位置和设计高程进行测设。<br>（3）隧道贯通误差的测定与调整<br>当隧道相向开挖到贯通面时，由于受到测角、量距、水准测量等误差的联合影响，线路在中线与高程两方面均会产生实际贯通误差。 为了保证线路中线平顺、断面尺寸与衬砌准确以及行车安全，必须进行贯通误差调整。<br>① 、隧道贯通误差的测定<br>在隧道贯通面任取一临时点E，分别由相向的两条导线附近的控制点测定该点的坐标，得两组坐标值（XE1，YE1），（XE2，YE2），由两边水准点测定E点高程为HE1，HE2。 由此△S=[（XE2-XE1）2+（YE2-YE1）2]1/2即为平面实际贯通误差。

Tunnel construction survey is an indispensable part in the process of tunnel construction. The quality of this work directly affects whether the tunnel can pass through according to the specified accuracy and the accuracy of construction setting out.<br>(1) control survey outside the tunnel<br>After entering the site and handing over the pile, our company organizes the survey technical force to retest the plane control network and elevation control network provided by the design unit, and the hole points are set accurately. After the field work is completed, the observation data shall be preliminarily processed, and the adjustment calculation and tunnel entry relationship calculation shall be carried out as required, and then it shall be reported to the supervising engineer for approval before use, so as to ensure the construction accuracy of the tunnel.<br>(2) control survey in tunnel<br>Traverse survey is mainly used for plane control survey in tunnel. As the tunnel is very short, the traverse point is not considered to be set in the tunnel, and one mirror point is set every 50m for setting out.<br>① selection and embedding of plane control points in the tunnel<br>The control points in the tunnel shall be selected in a place with good visibility and solid roof or floor rocks, so as to make the work safety and the control points easy to preserve. The traverse point in the tunnel is also used as the benchmark, and the method and requirements for stone embedding are the same as those for the traverse point outside the tunnel. Due to the busy construction and transportation in the tunnel and poor light, the signs exposed to the ground are easy to be damaged. The wire point is selected on one side of the central line. The top surface of the MARKSTONE shall be buried 10 ~ 20cm underground. On the principle of firmness, stability and convenience for use, it shall be covered with iron plate or plank, and it shall not be pressed on the metal signs. After the stone is buried, the red paint shall be used as the sign on the side wall, indicating the point number, mileage, etc., and the arrow shall be used to indicate the location of the buried point.<br>②. Traverse survey in tunnel<br>The traverse survey in the cave is all carried out by the total station. The measurement method is the same as that outside the cave. However, due to the severe measurement conditions in the cave, in order to reduce the influence of refraction error, we should choose to measure in a cool night and cloudy day. The goal must be aligned strictly with the goal. At the same time, the method of two collimation and two readings can be used, instrument attenuation, the calibration center, and collimation reading error.<br>③ elevation control survey in tunnel<br>A. leveling accuracy in tunnel<br>For the influence of ground and underground control survey on the through error, the equal influence distribution principle is adopted. The through tolerance of highway tunnel is 70mm, in which the error is 35mm, and the mean square error of elevation through in the tunnel is MH = 0.71 × 35 = 24.8mm. Because the leveling line is less than 5km, the use of equal external leveling meets the accuracy requirements.<br>B. leveling survey in tunnel<br>A. the horizontal control points and main traverse points are used for leveling in the tunnel as permanent benchmarks, and the construction traverse points are set as temporary benchmarks.<br>B. before the tunnel is run through, only branch leveling lines can be set for the benchmark in the tunnel. In order to increase the inspection conditions, multiple observation and round-trip observation must be carried out.<br>C. with the development of the tunnel and the extension of the benchmark, in order to meet the requirements of construction setting out and through accuracy, the benchmark with lower accuracy shall be set on the construction traverse point first, and then the benchmark with higher accuracy shall be set on the main traverse point.<br>D. due to poor intervisibility conditions in the tunnel, the distance between the instrument and the level gauge shall not exceed 50m.<br>C. trigonometric leveling of distance measurement in tunnel<br>The trigonometric leveling of distance measurement in the tunnel is completed together with the traverse survey of total station, that is, the traverse horizontal angle survey, the traverse side length survey and the traverse height difference survey. In order to reduce the accumulation of survey error, the transmission of traverse point elevation is carried out through the main line, and the elevation of construction traverse point is obtained from the observation of the main line point nearby.<br>④ measurement and setting of the middle line in the tunnel<br>In the early stage of tunnel excavation, based on the control points of the tunnel portal, the central line of the temporary tunnel is set out to guide the direction of tunnel excavation. When the tunnel is excavated to a certain distance and the control points in the tunnel are gradually established, the formal center line point shall be set to guide the lining construction of the tunnel. Since the tunnel is located on the horizontal curve line, one point shall be set every 5-10m for the temporary center line point and one point every 50m for the formal center line point. The central line can be measured by polar coordinate method. In order to prevent errors and improve the accuracy, the center dividing method should be used to measure the position of the middle pile.<br>⑤ measurement and setting of other structures in the tunnel<br>The survey and setting out of horizontal cross tunnels, drainage ditches and other structures in the tunnel can be carried out according to the relative position and design elevation of these structures and the central line.<br>(3) measurement and adjustment of tunnel through error<br>When the tunnel is excavated to the cut through surface in the opposite direction, due to the joint influence of angle measurement, distance measurement, leveling and other errors, the line will produce actual cut through errors in both the center line and the elevation. In order to ensure the smoothness of the middle line of the line, the accuracy of the section size and lining, and the driving safety, the through error must be adjusted.<br>①. Measurement of tunnel penetration error<br>Take any temporary point E on the tunnel through surface, and measure the coordinates of the point from the control points near the two opposite conductors, and get two sets of coordinate values (xe1, ye1), (xe2, Ye2). The elevation of point E is HE1, He2 determined by the benchmark on both sides. Thus △ s = [(xe2-xe1) 2 + (ye2-ye1) 2] 1 / 2 is the actual plane through error.<br>