（brokenchainage）Broken chainIt refers to the phenomenon that the stake numbers are not connected due to local rerouting or sectional measurement.Station overlapping scaleLong chain, intermittent station scaleShort chain。
P may be caused by local rerouting or error in spanMileage stakeNo. is not consistent with the actual distance, which is called "broken chain".
Where the new station is larger than the old station (the new route is longer than the old route), it is called "long chain".
Where the new station is smaller than the old station (the new route is shorter than the old route), it is called "short chain".
The so-called "broken chain processing" means that the whole line stations are not affected, and the middle chain is allowed to be broken, resulting in discontinuous stations.
Only the new station is used in the changed place, and the old station is still used in other unchanged places.
The old stake number of the whole stake in the nearest straight line segment shall be selected as the broken chain stake.Mark the new and old mileages and their relationship on the same broken chain pile.
example
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For example, when a route A is in location survey, local rerouting starts at AK2+356.400. After the old route A and the new route B pass through a continuous mileage respectively, the new route B overlaps with the old route A at BK3+426.200, where the old stake number is AK3+641.600.
There are two piles on the straight line segment after this coincident point:
AK3+660 is equivalent to BK3+444.600,
AK3+655.400 is equivalent to BK3+440.
Excuse me?Broken chainWhere should piles be selected?AK3+660
This broken chain isLong chainOr short chain?It is short chain (215.400m short chain)
How to write the log and station of the pile?Broken chain pile BK3+444.600=AK3+660 (short chain 215.4m)
If there is another chain break after the broken pile, and the chain is 65.4m long.What is the actual continuous mileage of AK8+500 at the end of the new road?
Total length of route=end pile mileage+sum of long chains - sum of short chains
