孔內(nèi)深層超強(qiáng)夯工法在濕陷性黃土地區(qū)高層建筑地基處理中的應(yīng)用

摘" 要：為探討孔內(nèi)深層超強(qiáng)夯（SDDC）工法在濕陷性黃土地區(qū)的應(yīng)用效果，采用SDDC工法的大直徑擠密樁作為某高層建筑地基處理方法，進(jìn)行復(fù)合地基承載力靜載荷試驗(yàn)、樁體壓實(shí)系數(shù)和樁間土擠密系數(shù)試驗(yàn)、樁身強(qiáng)度試驗(yàn)；依據(jù)試驗(yàn)數(shù)據(jù)指標(biāo)，按樁身強(qiáng)度和復(fù)合地基承載力特征值雙控的方法，確定復(fù)合地基承載力，并對建筑物在施工期間沉降和竣工后沉降觀測數(shù)據(jù)進(jìn)行搜集對比。試驗(yàn)結(jié)果表明，SDDC工法在濕陷性黃土地區(qū)高層建筑地基處理中消除地基濕陷、提高地基承載力、減小基礎(chǔ)沉降、加快施工速度、提高施工質(zhì)量和經(jīng)濟(jì)效益等方面具有明顯優(yōu)勢，表明該方法在濕陷性黃土地區(qū)處理地基是有效可行的。

關(guān)鍵詞：大直徑擠密樁；孔內(nèi)深層超強(qiáng)夯；高層建筑；地基處理；濕陷性黃土

中圖分類號：TU444" " " 文獻(xiàn)標(biāo)志碼：A" " " " " 文章編號：2095-2945（2023）28-00５５-0４

Abstract： In order to explore the application effect of super down-hole dynamic consolidation （SDDC） method in collapsible loess area， the large diameter compaction pile of SDDC method was used as the foundation treatment method of a high-rise building， and the static load test of bearing capacity of composite foundation， the compaction coefficient of pile and the compaction coefficient of soil between piles and the strength of pile were carried out. According to the index of test data， the bearing capacity of composite foundation is determined according to the double control method of pile strength and the characteristic value of bearing capacity of composite foundation， and the observation data of building settlement during construction and after completion are collected and compared. The test results show that the SDDC method has obvious advantages in eliminating collapsibility foundation of collapsible loess area in the high-rise building foundation treatment， increasing the subgrade bearing capacity， decreasing the foundation settlement ， speeding up the construction speed，and improving the construction quality and economic benefit， showing that the method in ground treatment of collapsible loess area is feasible and effective.

Keywords： large diameter compacted pile; super down-hole dynamic consolidation（SDDC）; high-rise building; collapsible loess area ground

濕陷性黃土是一類不良地質(zhì)條件，我國主要分布在西起祁連山，東至太行山，遍及甘肅、寧夏、陜西、山西的大部地區(qū)，其濕陷等級以Ⅱ級～Ⅳ級為主。濕陷性黃土遇水浸泡失去強(qiáng)度，同時過大的濕陷沉降變形導(dǎo)致基礎(chǔ)發(fā)生變形、裸露、懸空，甚至斷裂。因此，在濕陷性黃土地區(qū)進(jìn)行建筑設(shè)計和施工尤其是高層建筑施工就對地基處理提出了更高的要求。由于濕陷性黃土的土質(zhì)特點(diǎn)，濕陷性黃土地區(qū)地基的破壞主要來自水力侵蝕和重力侵蝕[1-3]。近年來，國內(nèi)外專家從消除黃土濕陷性方法、增強(qiáng)地基承載力等方面進(jìn)行了相對完善的研究，劉松玉等[4]對振桿密實(shí)法處理濕陷性黃土地基進(jìn)行了試驗(yàn)研究，結(jié)果表明振桿密實(shí)法處理后的土層錐尖阻力、側(cè)壁阻力和標(biāo)貫擊數(shù)較處理前顯著提高。……