Lu Wang

• Doctor of Philosophy
• Professor (Full) at Sichuan University

The variation of upstream slope of a submerged weir could significantly alter the local flow pattern and sediment transport. This paper presents an experimental investigation into local scour at submerged weirs with different upstream weir slope angles. In this study, 62 tests are carried out in a tilting recirculating flume, including 38 tests usi...

Local scour depth at weir-like structures is one of the most important engineering design parameters, which significantly affects the stability and safety of the structure. In this paper, the 80 years' research progress on scour at weir-like structures is reviewed. The scour classifications at weirs and the corresponding scour mechanism are elabora...

A better method to classify the resistances of bed in alluvial river was adopted to solve the problem of sand wave height prediction, by which a new relationship between bed form height and separation zone length in the lee side of sand wave was proposed via the analysis of mathematical model established by using energy conservation equation. Conse...

Rock weirs are eco-friendly grade-control structures. The flow over rock weirs can cause local scour, which threatens structural stability; thus, the scour depth is a critical parameter in rock weir design. However, the characteristics of clear-water scour at rock weirs under unsteady flow conditions remain unclear. This study conducted a series of...

Traditional monitoring techniques of flow and sediment are inadequate for the sparsely populated, the rivers in the Qinghai-Tibetan Plateau region which are experiencing amplified climate change. Inspired by the Euchiloglanis fish, this study developed a unique self-contained hydrodynamic observation platform to withstand the high velocities of mou...

Mountain rivers are characterized by wide grain size distributions and complex bed surface structures, which significantly affect bedload transport. Owing to the lack of a clear understanding of the quantitative influence of the bed surface structure on the bedload transport rate, existing methods for estimating the bedload transport rate in mounta...

Grade control structures (GCSs) are common river training structures constructed to prevent riverbed degradation. Existing scour predictors for GCSs are based on flume experiments with either no sediment supply or equilibrium sediment transport conditions, the quantitative impacts of sediment supply on the scour at submerged GCSs are still unclear....

Rock weirs are low-head river restoration structures. The present study comprised two sets of flume tests (i.e. fixed bed and moveable sand bed tests) to investigate the rock dislodgement process, which is a primary cause of the failure of rock weirs. The impacts of approach flow intensity, submergence, void ratio and scour of bed sediment on rock...

Migrating bedforms in alluvial rivers can exacerbate scour damage instream structures, leading to severe structure failures, which can cause large-scale and long-term issues with fluvial morphology and environment. This study investigates the interaction between scour fluctuation at instream structures and bedform migration based on large datasets...

Riverbank erosion is a common natural river process that threatens the security of in-stream structures as well as public and private properties. The impacts of riparian vegetation on the riverbank erosion processes are still unclear. This study conducted flume experiments with artificial riverbanks and living vegetation to investigate the effects...

Channel degradation can expose river-crossing cylindrical structures (e.g., pipelines, canals, and tunnels) that are completely buried in the riverbed, altering their surrounding flow patterns to cause scour that threatens their structural safety. This paper reports a case study of scour at a river-crossing canal in a degrading river. Based on the...

Sediment flux in rivers has dropped globally in the past decades due to the increasing anthropogenic stressors, leading to significant riverbed degradation that may endanger the instream structures, collapse the banks and affect the riverine environment. To stabilise riverbeds, grade control structures (GCSs) have been widely applied in degrading c...

Previous studies have primarily focused on the estimation of equilibrium scour depths around weirs, while overlooking the details of the temporal evolution of the live bed scour process of submerged weirs at the equilibrium stage. This study aims to investigate the relationships between fluctuating frequencies of the approaching bedforms and live b...

Bridge abutment-induced sediment scour in compound river channels is time-sensitive during floods, and, thus, estimating the scour rate has significance in design. In the current study, large-scale laboratory experiments were done to examine the influence of multiple factors on scour evolution, including channel geometry, bed mobility (clear-water...

This study conducts 12 flume tests on scour at a circular river-crossing tunnel in a degrading channel, using circular tunnels (diameter D = 50 ~ 110 mm) initially buried in a uniform sediment bed (median grain size d50 = 2.5 mm). The experiments applied different flow intensities (U/Uc = 1.3 ~ 2) with two approach flow depths (H = 50 and 100 mm)....

Local scour is an important design factor for submerged weirs. This study conducted a clear-water scour experiment at a submerged weir, using the particle tracking velocimetry technique to measure the flow field in the developing scour hole. The mean flow patterns, turbulence intensities and near-bed Reynolds shear stresses in the scour hole at dif...

Both global climate change and human activities are continuously impacting the abruptness and frequency of water-related natural disasters such as flash floods, debris flows, and landslides in mountainous areas, greatly threatening the safety of lives and properties. A recent rainfall-induced debris flow event happened on July 6, 2020 in the Chengh...

In mountainous areas, a river can widen from a single channel to a compound channel under the influence of geological conditions or human impacts, bringing about challenges in terms of flood control and channel regulation. This paper reports the results of tests conducted in a 26 m long flume with a uniform sediment bed (grain size = 0.5 mm), inves...

High‐flow intensity over a well‐developed static armour layer will significantly reduce the stability of a riverbed. However, the intensity at which the static armour layer would completely break is not known. In this study, laboratory flume experiments were conducted to analyze the response of the static armour layer to high‐flow intensity. The st...

River training structures are conventionally used to improve river stability and ecological conditions and to protect the upstream instream infrastructures from scour and erosion. A submerged weir is a typical river training structure usually built downstream of bridges for grade control. Flow over the weir can cause local scour, destabilizing both...

Riverbank erosion is a common natural river process that threatens the security of instream structures, as well as public and private property. In this study, two sets of tests were performed (direct shear tests and flume tests) to study the effects of riverbed soil composition on the stability of riverbanks. The results of the direct shear tests d...

Equilibrium clear-water scour depths predicted by existing equations based on the peak flow rate of a flood hydrograph can be overly conservative for submerged weirs in mild-slope sandy rivers, because the equilibrium timescale normally is much larger than the timescale of a flood event. Therefore it is important to understand the clear-water scour...

New laboratory data of local scour at submerged weirs are presented. The dimensionless scour depth downstream of a submerged weir in a uniform sediment bed is expressed as a function of dimensionless weir height, flow intensity, sediment coarseness, and weir slope. The existing and newly presented data are combined to evaluate the dependencies of d...

This paper conducted an undistorted scaled model test (geometric scale λL = 1:80; the others are derived scales based on Froude similitude) of a 1.3 km-long river reach in Shiting River, China, investigating the impacts of the grade control datum (GCD, defined as the crest elevation of the grade control structure) drop on the upstream bed morpholog...

This paper describes 64 experiments conducted in a sand-recirculating flume using coarse sand (d50 = 0.85 mm), investigating the interference of local scour between a circular pier (diameter D = 48 mm) and a downstream submerged weir (weir height z = 30 mm) with different separation distances L. The experimental results show that, for clear-water s...

This paper presents an experimental study of local scour at submerged weirs with different downstream slopes. Thirty-three tests of coarse sand (d50=0.85 mm) and 24 tests of fine sand (d50=0.26 mm) were carried out in a sand-recirculating flume. The tests for each sand type used four weirs with different downstream weir slopes (π/6, π/4, π/3, and π...