緊臨重力式擋土墻基坑設(shè)計(jì)計(jì)算研究

吳巍巍 彭文祥

摘 要：本文利用理正深基坑軟件對(duì)工程實(shí)例分別建立實(shí)際模型和等效荷載模型，模擬基坑開挖過程，將計(jì)算結(jié)果進(jìn)行對(duì)比分析，得出采用等效方法進(jìn)行設(shè)計(jì)計(jì)算時(shí)基坑偏于不安全，且等效時(shí)會(huì)忽略擋土墻與其背后土體的重度差異影響等結(jié)論，以期為類似基坑支護(hù)設(shè)計(jì)計(jì)算提供參考。

關(guān)鍵詞：重力式擋土墻；基坑支護(hù)；重度差異

中圖分類號(hào)：TU457 文獻(xiàn)標(biāo)識(shí)碼：A 文章編號(hào)：1003-5168（2018）07-0122-02

The Study on Design and Calculation of Foundation Pit Close

to Gravity Retaining Wall

WU Weiwei1，2 PENG Wenxiang1，2

（1.School of Geosciencesand Info-Physics， Central South University ，Changsha Hunan 410083；2.Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring（Central South University），Ministry of Education，Changsha Hunan 410083）

Abstract： We used Lizheng foundation pit software to establish the actual model and the equivalent model in this paper respectively， simulated the excavation process of foundation pit， and compared the simulation results. It was concluded that the foundation pit was unsafe when the equivalent method was used for the design and calculation， and the serious difference between the retaining wall and the soil behind the soil was ignored when the equivalent method was used. The conclusion provided reference for similar design and calculation of foundation pit support.

Keywords： gravity retaining wall；foundation pit support；severe difference

隨著城市的大規(guī)模建設(shè)，土地資源越來(lái)越稀缺，深基坑越來(lái)越多，城市高層建筑物一般是建在建筑物密集、人口稠密的地區(qū)[1，2]，基坑與既有建筑物之間的距離很小，有些甚至緊貼既有建筑物基礎(chǔ)進(jìn)行開挖。在實(shí)際工程中，經(jīng)常遇到深基坑附近存在既有的重力式擋土墻，有時(shí)深基坑邊緣距離擋土墻僅1m左右，在如此邊界場(chǎng)地下開挖基坑，若設(shè)計(jì)、施工不當(dāng)或保護(hù)措施不力，會(huì)導(dǎo)致?lián)跬翂突又ёo(hù)結(jié)構(gòu)被破壞，從而造成重大生命財(cái)產(chǎn)損失。對(duì)此類邊界基坑，目前通常是將擋墻及其背后土體等效為均布荷載作用在基坑頂水平面上，用朗肯土壓力計(jì)算公式進(jìn)行設(shè)計(jì)計(jì)算，但這種方法難以準(zhǔn)確反映開挖過程中擋土墻與基坑的相互影響。本文運(yùn)用理正深基坑軟件對(duì)實(shí)際模型及等效荷載模型進(jìn)行計(jì)算，得出此類邊界基坑支護(hù)時(shí)僅僅將重力式擋土墻等效為豎向均布荷載弱化了擋土墻及其后土體對(duì)基坑的實(shí)際影響。

1 工程簡(jiǎn)介和計(jì)算模型

1.1 工程概況……