Time filter

Source Type

Kuang C.,Tongji University | Pan Y.,Tongji University | Zhang Y.,Tongji University | Zhang Y.,China University of Mining and Technology | And 4 more authors.
Journal of Coastal Research | Year: 2011

This paper presents a detailed study of a beach nourishment project in Beidaihe, China. The study consists of a detailed assessment of a small-scale trial project that was carried out during May to June in 2008 to create two bathing sites on West Beach and a numerical evaluation of scheme options for the full project involving beach nourishment, groins, and submerged breakwaters. The monitoring data indicate that the nourished beach in the small-scale project was slowly eroding but in February of the following year the beach was still 20 m wider than it was before the project. The long-term shoreline evolution was then predicted using the generalized model for simulating shoreline change, which was calibrated to reproduce the posttrial project shoreline. The model indicates that without follow-up nourishment, the nourished beach created by the trial project will cease to be suitable for bathing in just 2-3 years. As to the full project the numerical evaluation of various scheme options indicates that the east groin plays a key role in protecting the beach in the long term and the removal of a rock jetty at east end of the beach in 2002 is identified as one of the major causes for the present severe erosion of West Beach. On the basis of the simulation results an optimum scheme for the project is proposed. © 2011, the Coastal Education & Research Foundation (CERF).

Liu Y.,Ocean University of China | Li H.-J.,Ocean University of China | Zhu L.,Qinhuangdao Mineral Resource and Hydrogeological Brigade
Applied Ocean Research | Year: 2016

This study examines the Bragg reflection of water waves by multiple submerged semi-circular breakwaters. The multipole expansions combined with the shift of polar coordinates are used to develop full linear potential solutions of the problem. In the full solutions, the obliquely and normally incident waves are independently considered. Experimental tests are carried out to measure the reflection and transmission coefficients of the breakwaters at different wave periods and body spacings. The analytical results are in reasonable agreement with the experimental data. The peak reflection coefficient of multiple submerged semi-circular breakwaters and the bandwidth of Bragg reflection are carefully examined by numerical examples. Some significant results for practical application are discussed. © 2016 Elsevier Ltd.

Zhang Y.,China University of Mining and Technology | Zhang Y.,Tongji University | He L.,Tongji University | Kuang C.,Tongji University | And 4 more authors.
Acta Oceanologica Sinica | Year: 2012

Beach nourishment is a common coastal management strategy used to protect beach from erosion along the sandy coastlines. This method has been successfully applied to an emergency project at the West Beach of Beidaihe in the summer of 2008 and the full West Beach nourishment project in 2009-2010, which is the direct base of this study. Some basic information about the emergency engineering area at the Middle Beach is firstly described. The shoreline change of this area, including the analysis of beach width in five monitoring profiles in the bathing places of Middle Beach, is then discussed. After that a numerical model based on one-line theory is established and the numerical results agree well with the measured shorelines, which indicates that the model is appropriate and is qualified to predict the shoreline change of the Middle Beach. With the same model and parameters, long-term performance of the project is predicted, and the result shows that without follow-up nourishment and project, the bathing places can remain suitable for bathing for about 10 a. It is suggested to nourish the beach in time and carry out the beach nourishment project for the full Middle Beach in Beidaihe. © The Chinese Society of Oceanography and Springer-Verlag Berlin Heidelberg 2012.

Kuang C.,Tongji University | He L.,Tongji University | He L.,Nagoya Institute of Technology | Gu J.,Shanghai Ocean University | And 5 more authors.
Journal of Coastal Research | Year: 2014

Kuang, C.; He, L.; Gu, J.; Pan, Y.; Zhang, Y.; Yang, Y.; Qiu, R., and Zhang, J., 2014. Effects of submerged breakwater on hydrodynamics and shoreline change of the East Beach of Beidaihe, Bohai Bay, China. The beaches in Beidaihe of Bohai Bay of China have been eroded since 1950s, clearly evidenced by sand coarsening, rock outcropping, and slope steepening. Beach nourishment is a common coastal management strategy used to protect beaches from erosion along sandy coastlines, and it has already been applied to recover several beaches of Beidaihe since 2008. In this paper, the effects of a submerged breakwater used as part of a beach nourishment project on hydrodynamics and shoreline changes of the East Beach of Beidaihe are presented. First, the brief descriptions of phase I and phase II of the beach nourishment project of East Beach are given. And then numerical models, including tidal current model, wave model, and one-line model for simulating hydrodynamics (tidal currents and waves) and shoreline changes are established and verified by field measurements. These well-verified numerical models are adopted to compute the tidal current fields, wave fields, and shoreline changes of East Beach with and without the submerged breakwater. The results show that the submerged breakwater plays a very important role in protecting East Beach to a certain degree. The effects of alterations of the freeboard and the width and the length of the submerged breakwater on shoreline changes are also discussed, and the results show that increasing the above three parameters will better protect the beach. Overall, a submerged breakwater can play a certain role in protecting a beach against erosion; additional beach nourishment is needed to stabilize East Beach in long term. © Coastal Education & Research Foundation 2014.

Pan Y.,Hohai University | Kuang C.,Tongji University | Gu J.,Shanghai Ocean University | He L.,Tongji University | And 4 more authors.
Journal of Coastal Research | Year: 2014

Pan, Y.; Kuang, C.; Gu, J.; He, L.; Zhang, Y.; Yang, Y.; Qiu, R., and Zhang, J., 2014. Assessment of a measure for water exchange strengthening of artificial headland bays based on shoreline change and flushing time. Artificial headlands are used around the world to form headland bays to contain beach materials. However, the artificial headland would weaken the water exchange in the bay and in some cases would make the water quality deteriorate. In this paper, we propose reserving a tidal channel in the landward end of the artificial headland, thus enabling the tidal current to pass through the channel, as a solution. The effects of the tidal channel on the weakening of beach protection and the strengthening of water exchange were investigated via numerical studies based on a beach nourishment project. A shoreline change model was set up to investigate the weakening of the beach protection. Four project schemes were simulated, and the results indicated that weakening of the beach protection is acceptable and the response of the shoreline to the tidal channel is influenced by the state of the beach. A three-dimensional (3D) flow model and a 3D constituent transport model were applied to evaluate the strengthening of water exchange using flushing time as the indicator. The results indicate that the reservation of the tidal channel induces an approximate 50% reduction in flushing time. The specific reduction amount of the flushing time is influenced by the length of the tidal channel, the tidal condition, and the direction of the artificial headland. The conclusions suggest that the tidal channel is a feasible and effective measure to strengthen the water exchange in an artificial headland bay at the cost of an acceptable loss of beach protection effect. © Coastal Education & Research Foundation 2014.

Discover hidden collaborations