Soft soil roadbed settlement monitoring method and device

Abstract

The invention discloses a monitoring method for sedimentation of soft soil foundation and the device. Procedures are that firstly, working reference pile is buried; secondly displacement sensor is installed; thirdly cable is connected; fourthly sedimentation steel plate is set; fifthly displacement is monitored and data are read; sixthly data is processed. Cement sand pile is connected with lower-layer PVC pipe and pre-buried steel plate is embedded at the top of pile. Four clip springs are welt on the pre-buried steel plate. The foundation of displacement sensor is fixed on the pre-buried steel plate tightly by clip springs. The foundation is connected with pull rod. The pull rod mated with spring is connected ball head. The ball head is connected with sedimentation steel plate. Shell, foundation, pull rod, spring and ball head are covered by bellows. The sedimentation steel plate is connected with upper-layer PVC pipe and the foundation of sensor is connected with the cable. After the cable passes through the hole and it is connected with digital display instrument through the cable protective pipe. The invention can not be constrained by construction and weather conditions and can realize quick, accurate, continuous and easy measurement for sedimentation value of soft soil foundation. The measuring accuracy is high and foundation sedimentation after opening for traffic can be monitored for a long time.

Description

technical field [0001] The invention relates to foundation deformation monitoring of geotechnical engineering, in particular to a method for monitoring settlement of expressway soft soil roadbed, and at the same time relates to a settlement monitoring device for expressway soft soil roadbed. Background technique [0002] Geotechnical deformation monitoring is an indispensable technical measure in engineering construction, and an important basis for technical decision-making in geotechnical engineering design, construction and operation. The code requires that soft soil subgrade settlement must be monitored during expressway construction. At present, the most widely used method for soft soil subgrade settlement monitoring is the surface settlement slab method, that is, to bury the surface settlement slab and measure the elevation change of the measuring rod on the settlement slab with a level to obtain the subgrade settlement. Simple, low cost and other advantages, but there ...

AI Technical Summary

Problems solved by technology

At present, the most widely used method for soft soil subgrade settlement monitoring is the surface settlement slab method, that is, to bury the surface settlement slab and measure the elevation change of the measuring rod on the settlement slab with a level to obtain the subgrade settlement. Simple, low cost and other advantages, but there are the following disadvantages that are difficult to overcome: the measuring rod of the settlement plate must be continuously raised as the embankment is filled, which increases the difficulty of operation and the cumulative error; the measuring rod must be exposed or buried under the road surface , the former has a greater impact on construction and is easily damaged by rolling machinery, etc., while the latter needs to dig out the measuring rod every time it is measured, the workload is heavy and it is not easy to find the location, the monitoring efficiency is low, and the compacted roadbed is damaged The integrity of the construction; construction machinery can not be close to the measuring rod for rolling, only small machinery can be used for rolling, so the compaction quality is worse than that of the surrounding area, and it is difficult to meet the control requirements; each monitoring section needs to be in a place that is not affected by the settlement of the roadbed The measurement reference point is buried deep in the far position, the measurement distance is long, it is difficult to ensure the condition of visibility, the workload and intensity are large, and the measurement accuracy is not good. It cannot be measured in bad weather such as strong wind, rain, snow, fog or at night. ; When the embankment is high, more measuring stations are required for measurement, the accuracy is reduced, and the operation is difficult; the monitoring cannot be continued after the road construction

[0003] There are also a small number of water cup monitoring methods, which can realize continuous monitoring of the settlement of the entire section, but need to set up a base station next to the embankment, and the elevation of the base station also needs to be checked through peripheral reference points, and the accuracy is not satisfactory; Settlement measurement is one of the high-tech, but in addition to high precision, it has the disadvantages of high price, small range, and expensive reading instrument, and it also needs to be checked by peripheral reference points

[0004] To sum up, it can be seen that the currently commonly used soft foundation settlement monitoring method is not ideal. Therefore, a new monitoring method and device must be developed to overcome the high test cost, heavy workload, poor accuracy and impact on construction of the existing settlement monitoring method. and other shortcomings, the new device and method combined with displacement sensors and working reference piles will not affect the embankment construction, and will not be limited by construction and weather conditions, and realize all-weather, high-precision, rapid and continuous monitoring of soft soil subgrade settlement

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