Development and applications of debris mobility models in Hong Kong

Kwan, J.S.H.; Sze, Eric H. Y.; Lam, Carlos; Law, Raymond P.H.; Koo, R.C.H.

doi:10.1680/jgeen.21.00008

Cited by 10 publications

(5 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…where the coe cient k=1 and α=2.5 for rigid barriers according to Kwan (2012). Figure 22 shows the comparison of the peak impact forces obtained by equation 2 and PFC simulations in this study.…”

Section: Discussionmentioning

confidence: 90%

Three-dimensional modeling of the impact behavior of debris flows in areas affected by earthquakes

Dai

Jiang

2023

Nat Hazards

View full text Add to dashboard Cite

The 2008 Wenchuan earthquake triggered many landslides and caused high volumes of loose solid material to collect in gully drainage areas; over time, this material eroded and became the source material for multiple debris ows. On August 13, 2010, a heavy rainstorm struck the areas that were impacted by the Wenchuan earthquake. The resulting debris ows caused more than 2,000 deaths and destroyed numerous buildings, bridges, and tra c facilities. To mitigate and/or prevent the negative consequences of such disasters in the future, it is important to have reliable and effective methods for predicting the impact behavior of these debris ows. In this study, we investigated the impact behavior of debris ows in post-earthquake areas using a three-dimensional model that is based on the particle ow code PFC3D.We veri ed our model by simulating a granular ow model test in a laboratory. We quanti ed the ow process and the impact force of the granular material; by comparing our model data to the test data, we found that the PFC3D model was capable of accurately simulating the dynamic behavior of the granular ows. We then used our model to estimate the propagation processes and the impact forces exerted on check dams by two large debris ows that occurred in the Wenchuan earthquake area. The results agreed with data collected during eld surveys, and the PFC3D model can reproduce the dynamic behavior of debris ows in areas that had recently experienced signi cant seismic activity.

show abstract

Section: Discussionmentioning

confidence: 90%

Three-dimensional modeling of the impact behavior of debris flows in areas affected by earthquakes

Dai

Jiang

2023

Nat Hazards

View full text Add to dashboard Cite

show abstract

“…In the early versions of the design guidelines in Hong Kong, this coefficient was specified as 2.0 and 2.5 for flexible (Kwan and Cheung, 2012) and rigid (Kwan, 2012) barriers, respectively. These recommended dynamic pressure coefficients implicitly allow for the presence of particles smaller than 0.5 m (Kwan et al, 2018). Flexible barriers typically correspond to a lower dynamic pressure coefficient than those of rigid barriers because of their deformable and pervious nature that allows certain debris to pass through upon impact.…”

Section: Results At the Time The Prediction Is Madementioning

confidence: 99%

Class A Prediction Symposium on Debris Flow Impact Forces on Single and Dual Barriers

Ng,

CHOI,

LILU

et al. 2023

HKIE Transactions

View full text Add to dashboard Cite

Over recent years, significant advances have been made in the modelling of the impact dynamics between debris flows and single and dual rigid and flexible barriers. Numerical tools and analytical formulations have been proposed to predict the impact force, runup height, barrier deformation, and overflow and landing dynamics. However, there remains a dearth of well-recognised tools that can be used in routine engineering design practice because their reliability is unclear. On 8 and 9 May 2022, a virtual Class A Prediction Symposium on Debris Flow Impact Forces on Single and Dual Barriers was held to evaluate the reliability of existing design tools and identify areas for improvement to advance the current state of barrier design. The symposium was organised by The Hong Kong University of Science and Technology, Norwegian University of Science and Technology, Institute of Mountain Hazards and Environment of the Chinese Academy of Sciences, and the Geotechnical Engineering Office of the Civil Engineering and Development Department of the HKSAR Government. This paper summarises the existing research on flow-barrier interaction, and details of the symposium, including the prediction cases and results, roundtable discussion, and future research directions.

show abstract

“…Details can be found in Kwan et al (2019). Similar LS-DYNA modelling techniques for flexible barriers under impact have also been adopted by other geotechnical practitioners (Koo et al, 2017;Cheung et al, 2018;Kwan et al, 2021).…”

Section: Results Of α Valuesmentioning

confidence: 99%

Study of dynamic debris impact load on flexible debris-resisting barriers and the dynamic pressure coefficient

Lam¹,

Sze²,

Wong³

et al. 2022

Can. Geotech. J.

View full text Add to dashboard Cite

The use of steel flexible barriers to mitigate landslide risk on natural hillsides is becoming common in the last decade in Hong Kong. The current design approach for this kind of barrier structure involves the adoption of the hydrodynamic load model to predict dynamic impact forces, followed by non-linear structural analyses of flexible barriers using numerical programs based on the pseudo-static method. From local guidelines, the dynamic pressure coefficient is taken as 2.0. This empirically considers the effect of impacts from boulders up to 2.0m in diameter. With a view to rationalising the design approach, a series of physical impact tests and numerical analyses was conducted to investigate the dynamic impact on flexible barriers and the resulting barrier response. The tests involved up to 9m³ of debris resisted by a 1.5m high steel barrier, conducted at the 28m long flume facility at the Kadoorie Centre, Hong Kong. Numerical modelling using computer programs LS-DYNA and NIDA-MNN was conducted to analyse the dynamic response. The study aims to evaluate the dynamic pressure coefficient and to verify the current design approach. Results indicate that a coefficient of 1.0 is in general appropriate for design purposes for debris comprising primarily water and fine-grained particles.

show abstract

Development and applications of debris mobility models in Hong Kong

Cited by 10 publications

References 17 publications

Three-dimensional modeling of the impact behavior of debris flows in areas affected by earthquakes

Three-dimensional modeling of the impact behavior of debris flows in areas affected by earthquakes

Class A Prediction Symposium on Debris Flow Impact Forces on Single and Dual Barriers

Study of dynamic debris impact load on flexible debris-resisting barriers and the dynamic pressure coefficient

Contact Info

Product

Resources

About