利用水准仪进行水准路线的测量

单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,项目二 水准路线的测量,一、水准点和水准路线,1,.,水准点,用水准测量方法获得高程的高程控制点，称为水准点。一般用,BM(Bench Mark),表示。,根据水准点的重要程度及使用时间可把水准点分为：,永久性水准点,临时性水准点,（,1,）永久性水准点,关键词语：永久保存，固定标志，国家,等级,（,2,）临时性水准点,关键词语：临时使用，简易标志,2,.,水准路线,水准测量施测时所经过的路线。,水准路线的布设有单一水准路线和水,准网，其中单一水准路线有三种布设形式：,（,1,）闭合水准路线,（,2,）附合水准路线,（,3,）支水准路线,（,1,）闭合水准路线,从一个已知水准点,BM3,开始，沿各待测高程点,1,、,2,、,3,等点进行水准测量，最后又回到原水准点,BM3,，这种水准路线称为闭合水准路线,BM3,（已知）,h,1,h,2,h,3,h,4,h,5,1,2,3,4,提出问题：,结论：正是上述 ，因此闭合水准路线才具检校功能。,（,2,）附合水准路线,从一个已知水准点,BM1,开始，沿各待测高程,C,、,D,、,E,等点进行水准测量，最后又回到原水准点,BM2,，这种水准路线称为附合水准路线,结论,:,因,所以附合水准路线也具检校功能。,BM1,(,已知,),BM2,(,已知,),h,1,h,2,h,3,h,4,C,D,E,（,3,）支水准路线,从已知高程的水准点,BM1,出发，进行待定高程水准点,A,的,水准测量，这种既不闭合又不附合的水准路线，称为支水准路线。,BM,1,A,h,往,h,返,由于支水准路线不具检校功能，因此要进行往返测量，以资检核。,前后衔接：,转点与测站,在实际工作中常常会碰到以下等情况：,a,b,原因,:,两点地势起伏较大,b,a,原因,:,两点相距较远,视距长,150m,解决方法,:,在两点间设转点,安置多次仪器,进行连续观测。,如图示,不难看出：,各测站所得高差：,返回目录,下一节,转点：传递高程的临时立尺点。,如图中 、 等,测站：安置仪器的地方。,返回,二、水准测量施测方法与记录,（,1,）,水准仪至水准尺的距离,1,）视线长度的影响,2,）地面坡度的影响,A,H,A,C,H,B,h,AB,大地水准面,（,2,）水准测量施测方法与记录,如,已知水准点,BMA,的高程,H,A,48.145m,，现欲测定,B,点的高程,H,B,，由于,A,、,B,两点相距较远（或地势起伏较大），需分段设转点进行测量，具体施测步骤如下。,B,A,H,A,B,H,B,h,AB,大地水准面,TP1,h,1,后视点,前视点,(1),在已知高程的水准点,BMA,，转点,TP1,上立尺，然后测站安置水准仪；,前进方向,2.036,1.547,测站,测点,水准尺读数,/m,高差,/m,高程,/m,备注,后视读数,前视读数,+,-,BM,A,48.145,TP1,水准测量记录手册,(2),瞄准点,A,上水准尺,(,后视尺,),，精平,读数,并记录手册,同样再瞄准,TP1,上水准尺，精平读数,也记录手册,;,并计算两点间高差,测站,测点,水准尺读数,/m,高差,/m,高程,/m,备注,后视读数,前视读数,+,-,BM,A,2.036,48.145,TP1,测站,测点,水准尺读数,/m,高差,/m,高程,/m,备注,后视读数,前视读数,+,-,BM,A,2.036,48.145,TP1,测站,测点,水准尺读数,/m,高差,/m,高程,/m,备注,后视读数,前视读数,+,-,BM,A,2.036,0.489,48.145,TP1,1.547,A,H,A,B,H,B,h,AB,大地水准面,TP1,h,1,后视点,前视点,前进方向,测站,测点,水准尺读数,/m,高差,/m,高程,/m,备注,后视读数,前视读数,+,-,BM,A,2.036,48.145,TP1,1.547,A,H,A,B,H,C,h,AB,大地水准面,TP1,h,1,TP2,前进方向,2.036,1.547,后视点,前视点,后视点,前视点,(3),第,测站测完后,将水准仪搬至,站,点,A,点水准尺移至,TP2,上立尺，,TP1,上水准尺原地不动,只需翻转即可,;,测站,测点,水准尺读数,/m,高差,/m,高程,/m,备注,后视读数,前视读数,+,-,BM,A,2.036,0.489,48.145,TP1,1.547,TP1,TP2,A,H,A,B,H,B,h,AB,大地水准面,TP1,h,1,TP2,前进方向,h,2,1.743,1.436,后视点,前视点,后视读数,前视读数,水准测量记录手册,(4),在,站上重复,站操作步骤,读取,前、后视尺上读数,并记录手册,计算高差；,测站,测点,水准尺读数,/m,高差,/m,高程,/m,备注,后视读数,前视读数,+,-,BM,A,2.036,0.489,48.145,TP1,1.547,TP1,1.743,TP2,测站,测点,水准尺读数,/m,高差,/m,高程,/m,备注,后视读数,前视读数,+,-,BM,A,2.036,0.489,48.145,TP1,1.547,TP1,1.743,TP2,1.436,测站,测点,水准尺读数,/m,高差,/m,高程,/m,备注,后视读数,前视读数,+,-,BM,A,2.036,0.489,48.145,TP1,1.547,TP1,1.743,0.307,TP2,1.436,A,H,A,B,H,B,H,AB,大地水准面,TP1,TP3,h,1,TP2,前进方向,h,2,1.743,1.436,(5),重复上述过程,连续观测、记录，,直终点,B,结束。,A,H,A,B,H,B,h,AB,大地水准面,TP1,TP4,TP3,h,1,TP2,前进方向,h,2,1.743,1.436,A,2.036,1.547,1.676,1.034,h,3,1.244,1.765,h,4,1.418,1.889,h,5,测站,测点,水准尺读数,/m,高差,/m,高程,/m,备注,后视读数,前视读数,+,-,BMA,2.036,0.489,48.145,(,已知,),TP1,1.547,TP1,1.743,0.307,TP2,1.436,TP2,1.676,0.642,TP3,1.034,TP3,1.244,0.521,TP4,1.765,TP4,1.148,0.741,48.321,BM,B,1.889,(,待定,),辅,助,计,算,水准测量记录手册,对于记录表中的高差和高程必须进行计算校核。,校核内容如下：,测站,测点,水准尺读数,/m,高差,/m,高程,/m,备注,后视读数,前视读数,+,-,BMA,2.036,0.489,48.145,(,已知,),TP1,1.547,TP1,1.743,0.307,TP2,1.436,TP2,1.676,0.642,TP3,1.034,TP3,1.244,0.521,TP4,1.765,TP4,1.148,0.741,48.321,BM,B,1.889,(,待定,),7.847,7.671,1.438,1.262,辅,助,计,算,a-,b,=7.847-7.761=+0.176,h,=+1.438+(-1.262)=+0.176,故,a-,b=,h,H,B,-H,A,=+0.176,水准测量记录手册,3,、水准测量误差与注意事项,一、仪器误差,1,、水准管轴与视准轴不平行误差,2,、水准尺误差,二、观测误差,1,水准管气泡的居中误差,2,估读水准尺的误差,3,视差的影响误差,4,水准尺倾斜的影响误差,三、外界条件影响误差,1,水准仪下沉误差,采用“后、前、前、后”的观测程序，可减弱其影响。,2,尺垫下沉误差,采用往返观测的方法，取成果的中数，可减弱其影响。,3,地球曲率及大气折光的影响,大地水准面,B,A,b,a,b,a,b,a,r,f,c,H,A,H,B,地球曲率对读数的影响,大气折光对读数的影响,返回目录,下一节,（,4,）水准测量的注意事项：,6,条,4,、水准测量成果（内业）计算,内业计算前须对外业手册检查，检查无误后方可进行内业计算。,1.,高差闭合差及其允许值,水准路线中实测高差与理论高差的差值，称为高差闭合差。用 表示。,例如：,BM3,（已知）,h,1,h,2,h,3,h,4,h,5,1,2,3,4,根据高差闭合差概念,闭合水准路线：,同理：,附和水准路线：,支水准路线：,不难看出， 的大小反映水准测量成果的精度，要求 有一定限度。,因此，测量规范规定，等外水准测量高差闭合差的允许值：,2.,高差闭合差改正计算,高差闭合差在允许范围之内时，即可,进行高差闭合差的改正计算，即消除高差,闭合差。,改正原则与方法：,按与测站数或测段长度成正比例的原,则，将高差闭合差反号分配到各相应测段,的高差上，得改正后高差。即：,式中 ：,v,i,第,i,测段的高差改正数（,mm,）；,、,水准路线总测站数与总长度；,、,第测段的测站数与测段长度。,高差改正数的总和与高差闭合差大小相等，符号相反。即,3.,改正后的高差计算,各测段改正后高差等于各测段观测高差加上相应的改正数，即,式中,第,i,段的改正后高差（,m,）。,4.,各点高程计算,由起点高程逐一推算出各点高程。,四、实例讲解,（,2,）、附合水准路线的计算,下图是一附合水准路线等外水准测量示意图，,A,、,B,为已知高程的水准点，,H,A,72.536m,，,H,B,77.062m,，,1,、,2,、,3,为待定高程的水准点。,h,+2.336m,h,8.653m,h,+7.357m,h,3.456m,n,1,6,n,2,10,n,3,8,n,4,6,BMA,1,2,3,BMB,4,点号,距离,/km,测站数,实测高差,/m,改正数,/mm,改正后高差,/m,高程,/m,点号,备注,1,2,3,4,5,6,7,8,9,辅助,计算,1,填写观测数据和已知数据,h,+2.336m,h,8.653m,h,+7.357m,h,3.456m,n,1,6,n,2,10,n,3,8,n,4,6,BMA,1,2,3,BMB,点号,距离,/km,测站数,实测高差,/m,改正数,/mm,改正后高差,/m,高程,/m,点号,备注,1,2,3,4,5,6,7,8,9,BMA,辅助,计算,点号,距离,/km,测站数,实测高差,/m,改正数,/mm,改正后高差,/m,高程,/m,点号,备注,1,2,3,4,5,6,7,8,9,BMA,1,辅助,计算,点号,距离,/km,测站数,实测高差,/m,改正数,/mm,改正后高差,/m,高程,/m,点号,备注,1,2,3,4,5,6,7,8,9,BMA,1,2,辅助,计算,点号,距离,/km,测站数,实测高差,/m,改正数,/mm,改正后高差,/m,高程,/m,点号,备注,1,2,3,4,5,6,7,8,9,BMA,1,2,3,辅助,计算,点号,距离,/km,测站数,实测高差,/m,改正数,/mm,改正后高差,/m,高程,/m,点号,备注,1,2,3,4,5,6,7,8,9,BMA,1,2,3,4,辅助,计算,点号,距离,/km,测站数,实测高差,/m,改正数,/mm,改正后高差,/m,高程,/m,点号,备注,1,2,3,4,5,6,7,8,9,BMA,6,1,2,3,4,辅助,计算,点号,距离,/km,测站数,实测高差,/m,改正数,/mm,改正后高差,/m,高程,/m,点号,备注,1,2,3,4,5,6,7,8,9,BMA,6,2.336,1,2,3,4,辅助,计算,点号,距离,/km,测站数,实测高差,/m,改正数,/mm,改正后高差,/m,高程,/m,点号,备注,1,2,3,4,5,6,7,8,9,BMA,6,+2.336,1,10,8.653,2,3,BMB,辅助,计算,点号,距离,/km,测站数,实测高差,/m,改正数,/mm,改正后高差,/m,高程,/m,点号,备注,1,2,3,4,5,6,7,8,9,BMA,6,+2.336,1,10,8.653,2,8,+7.357,3,BMB,辅助,计算,点号,距离,/km,测站数,实测高差,/m,改正数,/mm,改正后高差,/m,高程,/m,点号,备注,1,2,3,4,5,6,7,8,9,BMA,6,+2.336,1,10,8.653,2,8,+7.357,3,6,+3.456,BMB,辅助,计算,点号,距离,/km,测站数,实测高差,/m,改正数,/mm,改正后高差,/m,高程,/m,点号,备注,1,2,3,4,5,6,7,8,9,BMA,6,+2.336,72.536,1,10,8.653,2,8,+7.357,3,6,+3.456,BMB,77.062,辅助,计算,2.,计算高差闭合差及其允许值,点号,距离,/km,测站数,实测高差,/m,改正数,/mm,改正后高差,/m,高程,/m,点号,备注,1,2,3,4,5,6,7,8,9,BMA,6,+2.336,72.536,1,10,8.653,2,8,+7.357,3,6,+3.456,BMB,77.062,30,+4.496,辅助,计算,成果合格,3.,高差闭合差改正计算,点号,距离,/km,测站数,实测高差,/m,改正数,/m,改正后高差,/m,高程,/m,点号,备注,1,2,3,4,5,6,7,8,9,BMA,6,+2.336,72.536,1,10,8.653,2,8,+7.357,3,6,+3.456,BMB,77.062,30,+4.496,辅助,计算,点号,距离,/km,测站数,实测高差,/m,改正数,/m,改正后高差,/m,高程,/m,点号,备注,1,2,3,4,5,6,7,8,9,BMA,6,+2.336,+0.006,72.536,1,10,8.653,2,8,+7.357,3,6,+3.456,BMB,77.062,30,+4.496,辅助,计算,点号,距离,/km,测站数,实测高差,/m,改正数,/m,改正后高差,/m,高程,/m,点号,备注,1,2,3,4,5,6,7,8,9,BMA,6,+2.336,+0.006,72.536,1,10,8.653,+0.010,2,8,+7.357,3,6,+3.456,BMB,77.062,30,+4.496,辅助,计算,点号,距离,/km,测站数,实测高差,/m,改正数,/m,改正后高差,/m,高程,/m,点号,备注,1,2,3,4,5,6,7,8,9,BMA,6,+2.336,+0.006,72.536,1,10,8.653,+0.010,2,8,+7.357,+0.008,3,6,+3.456,+0.006,BMB,77.062,30,+4.496,辅助,计算,点号,距离,/km,测站数,实测高差,/m,改正数,/m,改正后高差,/m,高程,/m,点号,备注,1,2,3,4,5,6,7,8,9,BMA,6,+2.336,+0.006,72.536,1,10,8.653,+0.010,2,8,+7.357,+0.008,3,6,+3.456,+0.006,BMB,77.062,30,+4.496,+0.030,辅助,计算,4.,改正后的高差计算,点号,距离,/km,测站数,实测高差,/m,改正数,/m,改正后高差,/m,高程,/m,点号,备注,1,2,3,4,5,6,7,8,9,BMA,6,+2.336,+0.006,72.536,1,10,8.653,+0.010,2,8,+7.357,+0.008,3,6,+3.456,+0.006,BMB,77.062,30,+4.496,+0.030,辅助,计算,成果合格,点号,距离,/km,测站数,实测高差,/m,改正数,/m,改正后高差,/m,高程,/m,点号,备注,1,2,3,4,5,6,7,8,9,BMA,6,+2.336,+0.006,+2.342,72.536,1,10,8.653,+0.010,8.643,2,8,+7.357,+0.008,+7.345,3,6,+3.456,+0.006,+3.462,BMB,77.062,30,+4.496,+0.030,辅助,计算,成果合格,点号,距离,/km,测站数,实测高差,/m,改正数,/m,改正后高差,/m,高程,/m,点号,备注,1,2,3,4,5,6,7,8,9,BMA,6,+2.336,+0.006,+2.342,72.536,1,10,8.653,+0.010,8.643,2,8,+7.357,+0.008,+7.345,3,6,+3.456,+0.006,+3.462,BMB,77.062,30,+4.496,+0.030,+4.526,辅助,计算,成果合格,改正后高差总和,=,终点高程,始点高程,4.526=,77.062-72.536,改正高差,=,实测高差,+,改正数,(6),项,=,(4),项,+(5),项,5.,高程计算,点号,距离,/km,测站数,实测高差,/m,改正数,/m,改正后高差,/m,高程,/m,点号,备注,1,2,3,4,5,6,7,8,9,BMA,6,+2.336,+0.006,+2.342,72.536,BMA,(,已知,),1,74.878,BM1,10,8.653,+0.010,8.643,2,66.235,BM2,8,+7.357,+0.008,+7.345,3,73.600,BM3,6,+3.456,+0.006,+3.462,BMB,77.062,BMB,(,已知,),30,+4.496,+0.030,+4.526,辅助,计算,成果合格,返回,二、闭合水准路线的计算,闭合水准路线成果计算的步骤与附合水准路线相同。,BMA,（已知）,h,4,=-1.424m,L,4,=0.8km,1,2,3,h,2,=+2.376m,L,2,=1.2km,h,3,=-3.366m,L,3,=1.0km,h,1,=+2.365m,L,1,=0.5km,下图是一闭合水准路线等外水准测量示意图，,A,为已知高程的水准点，,H,A,44.856m,，,1,、,2,、,3,为待定高程的水准点。,点号,距离,/km,测站数,实测高差,/m,改正数,/m,改正后高差,/m,高程,/m,点号,备注,1,2,4,5,6,7,8,9,BMA,0.5,+2.365,+0.007,+2.393,44.856,BMA,(,已知,),1,47.249,BM1,1.2,+2,.376,+0.017,+2.372,2,49.621,BM2,1.0,3.366,+0.014,3.352,3,46.269,BM3,0.8,1.424,+0.011,1.413,BMA,44.856,BMA,3.5,0.049,+0.049,0,辅助,计算,成果合格,H,往,1.532m,H,返,1.520m,BMA,1,三、支水准路线的计算,例, A,为已知高程的水准点，其高程,H,A,为,46.276m,，,1,点为待定高程的水准点，,h,往,和,h,返,为往返测量的观测高差。往、返测的测站数共,16,站，计算,1,点的高程。,1,计算高差闭合,2,计算高差容许闭合差,测站数：,因,|,f,h,|,|,f,允,|,，故精确度符合要求。,3,计算改正后高差,取往测和返测的高差绝对值的平均值作为,A,和,1,两点间的高差，其符号和往测高差符号相同，即,4,计算待定点高程,返回,下一节,