(1. 華南理工大學 安全科學與工程研究所，廣州 510640；
2. 華南理工大學 土木與交通學院，廣州 510640；
3. 廣東省安全生產(chǎn)科學技術(shù)研究院，廣州 510640)
摘 要: 為研究層狀石灰?guī)r采空區(qū)頂板的破壞特征及影響機制問題，在梅州某地下礦調(diào)研的基礎(chǔ)上，構(gòu)建采空區(qū)水平層狀優(yōu)勢節(jié)理頂板力學模型，推導其應(yīng)力分量表達式；結(jié)合M-C巖體強度準則，給出任意點巖體破壞判定值Z及其峰值數(shù)學式，分析頂板可能出現(xiàn)的變形破壞類型及失穩(wěn)特征。結(jié)果表明：頂板的頂部、下部、兩側(cè)翼等位置出現(xiàn)4個判定峰值區(qū)域，依照Z值大小排序，分別對應(yīng)脫落型(Ⅰ類)、撓曲型(Ⅱ類)、剪切型(Ⅲ類)等3種可能變形破壞形式。當Ⅰ、Ⅱ類變形破壞時，頂板具有“梯形拱”承載效應(yīng)；當Ⅲ類變形破壞時，頂板具有類似“工”型承載特征。頂板破壞類型受安全系數(shù)m、跨厚比n和側(cè)壓系數(shù)k0等因素影響，其中，m、n為可控因素，k0為不可控因素。當k0和n既定時，m僅影響Ⅰ、Ⅱ類或Ⅰ、Ⅲ類破壞類型之間的轉(zhuǎn)化，臨界處m分別為2.02和1.22；當m和n既定時，k0影響方式與m的方式相同，臨界處k0分別為1.25和1.33；當m和k0既定時，n將影響Ⅰ、Ⅱ、Ⅲ類等3種破壞類型之間轉(zhuǎn)化，臨界處n為1.6和3.5。采空區(qū)現(xiàn)場勘察結(jié)果驗證理論分析結(jié)果的合理性。成果為此類礦山采空區(qū)頂板參數(shù)選擇提供理論依據(jù)。
關(guān)鍵字: 石灰?guī)r采空區(qū)；變形破壞類型；影響機制；頂板安全系數(shù)；跨厚比
（1. Institute of Safety Science and Engineering, South China University of Technology, Guangzhou 510640, China;
2. School of Civil Engineering and Transportation, South China University of Technology, Guangzhou 510640, China;
3. Guangdong Academy of Safety Science and Technology, Guangzhou 510640, China）
Abstract:In order to study the failure characteristics and influence mechanism of the roof of goaf in layered limestone mine, based on the investigation of a underground limestone mine in Meizhou, a mechanical model of the roof with horizontal layered dominant joints was built, and the expressions of stress components were derived. Combined with the M-C strength criterion of rock mass, the failure judgment value Z at any point in roof and its peak value mathematical formula were given, and the possible failure type and deformation characteristics in instability process were analyzed. The results indicate that, there are four peak areas at the top, the bottom and both sides of the roof. According to the order of peak values of Z, there are three kinds of possible deformation failure forms, spalling type (Ⅰ), deflet type (Ⅱ) and shear type (Ⅲ). In class Ⅰ or class Ⅱ failures, the roof has the bearing effect of trapezoid arch; in class Ⅲ failure, the roof has the bearing effect similar to I-beam. The failure type of roof is affected by some factors, such as safety factor(m), span-thickness ratio(n) and lateral pressure factor(k0). m and n are controllable factors, and k0 is uncontrollable factors. When k0 and n are definite, m only affects the transformation between class Ⅰ and class Ⅱ or class Ⅰ and class Ⅲ failures, and the critical values of m are 2.02 and 1.22. When m and n are definite, k0 affects the same way as m, and the critical values of m are 1.25 and 1.33. When k0 and m are definite, n affects the transformation between class Ⅰ, Ⅱ and Ⅲ failures, and the critical values of m are 1.6 and 3.5. The results of field investigation of goaf verify the rationality of theoretical analysis results. The results provide theoretical basis for the selection of roof parameters in goaf of such mines.
Key words: limestone goaf; types of deformation and failure; influence mechanism; roof safety factor; span-thickness ratio
