(1. 北京科技大學(xué)土木與資源工程學(xué)院，北京 100083；
2. 金屬礦山高效開(kāi)采與安全教育部重點(diǎn)實(shí)驗(yàn)室，北京 100083)
摘 要: 為了研究不同養(yǎng)護(hù)齡期的分級(jí)尾砂膠結(jié)充填體在中等應(yīng)變率動(dòng)態(tài)沖擊加載下的動(dòng)力學(xué)特性，采用分離式霍普金森桿(SHPB)試驗(yàn)技術(shù)對(duì)16組48個(gè)充填體試樣進(jìn)行單次沖擊實(shí)驗(yàn)。結(jié)果表明：充填體動(dòng)態(tài)抗壓強(qiáng)度和動(dòng)態(tài)抗壓強(qiáng)度提高因子隨平均應(yīng)變率的增大呈線性增長(zhǎng)規(guī)律，而隨養(yǎng)護(hù)齡期的延長(zhǎng)，應(yīng)變率敏感性呈減小趨勢(shì)，動(dòng)態(tài)抗壓強(qiáng)度增幅則與沖擊速度呈負(fù)相關(guān)；充填體的韌性指數(shù)隨平均應(yīng)變率的增加呈指數(shù)函數(shù)增長(zhǎng)，且養(yǎng)護(hù)早期應(yīng)變率敏感性更高、增幅更顯著；充填體的吸收能、單位體積應(yīng)變能(比能量吸收)與應(yīng)變率、養(yǎng)護(hù)齡期均具有顯著正相關(guān)性，且養(yǎng)護(hù)早期的能量值應(yīng)變率敏感性更高、增幅更明顯；動(dòng)態(tài)沖擊加載下，破壞形態(tài)主要為軸向拉伸破壞，且平均應(yīng)變率越大、養(yǎng)護(hù)齡期越短，破壞越顯著。
關(guān)鍵字: 充填體；應(yīng)變率；養(yǎng)護(hù)齡期；動(dòng)態(tài)強(qiáng)度；單位體積吸收能；破壞形態(tài)
（1. School of Civil and Resource Engineering, University of Science
and Technology Beijing, Beijing 100083, China;
2. Key Laboratory of High-Efficient Mining and
Safety of Metal Mines, Ministry of Education, Beijing 100083, China）
Abstract:In order to study the dynamic characteristics of graded tailings cemented backfill with different curing ages under medium strain rate dynamic impact loading, the split Hopkinson bar (SHPB) test technology was used to conduct single impact test on 48 backfill samples of 16 groups. The results show that the dynamic compressive strength and dynamic compressive strength improvement factor of backfill increase linearly with the increase of average strain rate. As the curing age increases, the strain rate sensitivity shows a decreasing trend, and the dynamic compressive strength increase is negatively correlated with the impact speed. The toughness index of backfill increases exponentially with the increase of average strain rate, and the strain rate sensitivity of early curing period increases. The absorption energy and strain energy per unit volume (specific energy absorption) of backfill have significant positive correlation with strain rate and curing age, and the sensitivity of energy value strain rate in early curing period is higher and the increase is more obvious. Under dynamic impact loading, the failure mode is mainly axial tensile failure, and the higher the average strain rate and the shorter the curing age, the more significant the damage.
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