Device for measuring local scour depth around bridge piers

Abstract

The present invention provides a device for measurement of a local scour depth around a bridge pier. The device comprises a support platform, an elevator mechanism, a measurement platform, a monitoring probe and a control system. The support platform is fixed at the top or the body of the bridge pier; the elevator mechanism is installed on the support platform; the measurement platform is hanged at the lower end of the elevator mechanism; the monitoring probe is fixedly arranged on the measurement platform; and the control system is installed on the support platform or the top of the bridge pier, is connected with the elevator mechanism and the monitoring probe through cables and can calculate the current scour depth of the measurement points at the surface of a riverbed according to the current height value of monitoring probe and the distance between the monitoring probe and the measurement points at the surface of the riverbed. The device provided by the invention is easy to install and maintain, safe and reliable in flood season, and high in precision and monitoring efficiency, etc. The device for measurement of the local scour depth around a bridge pier does not need to punch at the surface of the bridge pier and cannot damage the structure of the bridge pier so as to easily obtain the permission of the bridge management department; and moreover, the whole installation process is completed above the water with no need for underwater work, and therefore the installation process is easy to realize.

Description

technical field [0001] The invention relates to the technical field of river bed scour depth measurement, in particular to a device for measuring local scour depth around bridge piers. Background technique [0002] The bridge across the river is an important part of the modern transportation network and is crucial to the development of the national economy and society. After the bridge piers are built in the natural channel, the water flow around the piers is seriously disturbed, forming three-dimensional and unsteady flow structures such as downflow and horseshoe vortex. These structures significantly increase the sand-carrying capacity of the water flow, resulting in local scour of the riverbed around the piers. Especially when a flood occurs during the flood season, due to the large flow rate and fast flow rate, the riverbed around the pier is easily scoured excessively, exposing the foundation of the pier, threatening the safety of the bridge, and even causing major acci...

AI Technical Summary

Problems solved by technology

The existing non-contact scour depth monitoring device can avoid underwater operations. By installing multiple sensors on the bracket and using a rotating bracket, the scour depth of multiple measuring points upstream and downstream of the pier can be measured to improve monitoring efficiency, but there are also Several key defects: first, the propagation speed of ultrasonic waves in water is affected by factors such as temperature and sediment concentration, and the data measured under different seasons and water flow conditions may have large errors; second, the ultrasonic echo signal 37 varies with the propagation distance However, natural rivers often have the dual characteristics of large water depth and high sediment concentration during the flood season, which makes the signal of the ultrasonic rangefinder very weak during the flood season, making it difficult to measure reliable scour depth data; Third, there are often a large number of weeds and other floating objects on the surface of natural rivers during the flood season. When these floating objects are attached to the bracket and the sensor, it will not only cause the sensor to fail, but may also crash the entire measurement device; fourth, in order to Fixing the bracket on the bridge pier usually requires opening holes on the bridge pier, which is difficult to obtain the permission of the bridge management department; fifth, because the bracket is a cantilever beam structure, the longer the bracket is, the worse the stability is, and it is easy to cause measurement errors due to swinging

[0007] To sum up, the local scour monitoring devices in the prior art usually need to work underwater and drill holes on bridge piers, which is technically difficult and restricted by supervision; at the same time, natural rivers have fast flow velocity, large water depth, and sediment in the flood season. High concentration, floating objects on the surface, and a large number of pebbles moving at the bottom are easy to wash away, crash the monitoring device or make the scour depth sensor invalid; thirdly, the existing non-contact local scour depth monitoring device does not consider the speed of sound wave propagation with water flow conditions. changes, the error is relatively large; finally, the existing device can only monitor the local area around the pier, and the monitoring efficiency is low

The above defects prevent the existing monitoring devices from being used for real-time on-line monitoring of local scouring depths of bridge piers on large rivers and rivers, which seriously restricts the improvement of bridge maintenance and management levels in our country.

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