海洋风化花岗岩崩解特性试验与离散元模拟研究

Experimental and Discrete Element Simulation Study on Disintegration of Marine Weathered Granite

针对海上风电嵌岩桩基础的施工过程中风化花岗岩的浸水软化崩解对施工安全的影响问题,通过设计浸水崩解装置,开展海洋风化花岗岩的浸水崩解试验,分析风化程度及酸碱溶液对风化花岗岩浸水崩解的影响规律,探究海洋风化花岗岩浸水崩解的机理,并使用离散元模拟风化花岗岩浸水崩解的过程.研究结果表明:花岗岩的风化程度对其浸水崩解速率和程度影响显著,随着花岗岩风化程度的提高,其浸水崩解程度从无明显崩解逐渐发展到部分崩解及完全崩解;黏土矿物胶结作用的丧失是海洋风化花岗岩崩解的主要原因,风化花岗岩中的金属氧化物在酸性溶液中的反应会导致其崩解程度增大.基于平行黏结接触模型建立的离散元模型,可以模拟风化花岗岩的浸水崩解全过程.

Aiming at the impact of water-soaked soft disintegration of weathered granite on construction safety during the construction of rock-socketed monopile foundations for offshore wind turbines,the disintegration tests of marine weathered granite were carried out by designing a disintegration test apparatus.The influence of granite weathering degree and solution pH on the disintegration of granite was investigated,and the mechanism of disintegration of marine weathered granite was revealed.Furthermore,a numerical simulation of the disintegration of weathered granite was implemented based on the discrete element method.The research results show that the weathering degree of granite has a significant impact on the rate and degree of its disintegration.As the weathering degree of granite increases,the degree of disintegration changes from no obvious disintegration to partial disintegration and complete disintegration.The loss of clay mineral cementation is the main reason for the disintegration of marine weathered granite.The reaction between metal oxides in weathered granite and acidic solutions leads to an increased degree of disintegration.The discrete element model established on the basis of parallel bonding contact model can simulate the entire process of disintegration of weathered granite.