- 摘 要
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（1 銅陵市建設(shè)投資控股有限責(zé)任公司， 銅陵 244000； 2 銅陵市建筑工程施工圖設(shè)計文件審查有限公司， 銅陵 244000；3 銅陵市建設(shè)工程質(zhì)量監(jiān)督監(jiān)測有限公司， 銅陵 244000）
［摘要］結(jié)合某33層住宅樁端基巖厚度小于3d和5m這一問題，詳細(xì)分析了其產(chǎn)生原因及處理方法。其原因為：基巖面傾斜、超前鉆或樁基的傾斜導(dǎo)致超前鉆見巖標(biāo)高與樁基全斷面見巖標(biāo)高相差較大，且未重新進(jìn)行補鉆；或樁端3d和5m以內(nèi)有溶洞，但超前鉆擦溶洞邊而過從而未能發(fā)現(xiàn)溶洞。其處理方法是：利用樁基承載力計算沒有計入側(cè)阻力、大多數(shù)樁承載力未用足等有利因素，結(jié)合不同位置的溶洞對樁承載力影響程度的不同進(jìn)行綜合分析，從而減少處理數(shù)量；當(dāng)必須處理時，可采用“高壓注漿置換溶洞充填物”的方法處理，也可采用“新增樁基+托換梁”的方法處理。
［關(guān)鍵詞］溶洞； 樁端基巖厚度； 超前鉆； 基巖面傾斜； 見巖標(biāo)高； 高壓注漿法
中圖分類號：TU473.1+6文獻(xiàn)標(biāo)識碼：A文章編號：1002-848X(2019)17-0136-06
Analysis and treatment of insufficient pile-end bedrock thickness of a 33-storey residential building in karst area
Chu Jun1, Li Guosheng2,3
（1 Tongling Construction Investment and Holding Co., Ltd., Tongling 244000， China; 2 Tongling Building Engineering Drawings Design Documents Examination Co., Ltd., Tongling 244000， China; 3 Tongling Construction Engineering Quality Supervision and Testing Co., Ltd., Tongling 244000， China）
Abstract:The pile-end bedrock thickness of a 33-storey residential building was less than 5m and 3 times of pile diameter. The causes and treatment methods for this problem were analyzed in detail. There were two main reasons. First, bedrock surface inclination, advance drilling or pile foundation inclination led to the great difference between rock elevation of advanced drilling and rock elevation of full cross-section pile foundation, and no additional drilling was carried out when this problem was identified. Second, there were karst caves within distance of 5m and 3 times of pile diameter from the pile end, but karst caves was not found because advanced drilling might brush against the edge of karst caves. The treatment methods were as follows. Some favorable factors could be manipulated such as side resistance not taken into consideration in the calculation of bearing capacity of pile foundation and the bearing capacity of most piles not used fully, and comprehensive analysis was carried out according to the different influences of karst caves at different locations on pile bearing capacity, thus reducing the number of treatments. When the problem had to be dealt with, the method of “replacing karst cave fillings with high-pressure grouting” or the method of “adding pile foundation + underpinned beam” could also be used.
Keywords:karst cave; pile-end bedrock thickness; advanced drilling; bedrock surface inclination; rock elevation; high-pressure grouting method
作者簡介：儲珺，學(xué)士，高級工程師，Email：358208048@qq.com。
