【正文】 具 ， 主要包括 ： 成孔的鉆機(jī)、泥漿循環(huán)設(shè)備、鉆桿、鉆頭與保徑圈，成樁的導(dǎo)管、料斗、球塞、混凝土拌制與輸送設(shè)備 。 圖一： 護(hù)筒 挖坑埋放法 鋼護(hù)筒采用 5～ 10mm 厚鋼板加工制成，其內(nèi)徑大于鉆頭直徑 200mm，每個(gè)鋼護(hù)筒頂部開設(shè) 1 個(gè)溢漿口，并高出地面 ～ ， 護(hù)筒采用比設(shè)計(jì)樁徑大 2030CM 的鋼護(hù)筒 ，護(hù)筒為鋼護(hù)筒，壁厚 10mm，護(hù)筒定位時(shí)，先以樁位中心為圓心，根據(jù)護(hù)筒半徑在土上定出護(hù)筒位置， 鋼護(hù)筒中心應(yīng)與樁中心重合，偏差不得大于 50mm。 （見圖二） 圖二：鉆機(jī)就位 鉆孔灌注樁施工前應(yīng)對施工場地整平壓實(shí)，就地地為深水區(qū)或淤泥層較厚時(shí)，應(yīng)搭設(shè)事 情平臺(tái)應(yīng)建立附合于布局物整體測量控制中的子控制網(wǎng) (包括平面控制與高程控制 )，且所有測量必須有多余觀測對擬施工樁位進(jìn)行放樣，并在另一測站進(jìn)行復(fù)核有前提時(shí)，應(yīng)用鋼尺對前后左右的樁位進(jìn)行相互校核在灌注樁施工中樁位的控制必須高度重視，確保無誤，一旦發(fā)生樁位錯(cuò)誤將難以彌 補(bǔ) 。 （見圖三） 圖三：泥漿制備與使用 制備的泥漿指標(biāo)應(yīng)達(dá)到： 比重：黏土、巖層為 ～； 黏度：黏土、巖層為 18～ 24 秒 ； PH 值：大于 ； 含砂率：小于 4%； 膠體率：大于 95%； 鉆機(jī)就位、對中、鉆進(jìn) 鉆孔 工藝 過程 沖擊鉆鉆孔工藝 ① 開鉆前應(yīng)注意的事項(xiàng) 10 開鉆前，在護(hù)筒內(nèi)多加一些粘土。 ③ 抽碴時(shí)應(yīng)注意的幾個(gè)問題 A 及時(shí)向孔內(nèi)補(bǔ)漿或補(bǔ)水，如向孔內(nèi)投放粘土自行造漿，在抽碴后隨著沖擊投放粘土，不宜一次倒進(jìn)很多，防止粘結(jié)。鉆至刃腳下 1m 后，可按土質(zhì)以正常速度鉆進(jìn)。 開孔時(shí)采用小沖程，使初成孔堅(jiān)實(shí)、豎直、圓順，能起到導(dǎo)向作用，并防止孔口崩塌。 12 f 在鉆孔排渣、提鉆頭除 土或因故停鉆時(shí)，應(yīng)保持孔內(nèi)具有規(guī)定的水位和要求的泥漿相對密度和黏度。終孔檢查后，應(yīng)迅速清孔，不得停閑過久。根據(jù)鉆孔灌注樁深度，控制清孔換漿到混凝土開始澆灌之間的時(shí)間 ；為避免孔底沉渣太厚，規(guī)定必須進(jìn)行第二次反循環(huán)清孔及測量沉渣厚度；待符合要求，其他一切準(zhǔn)備工作均已就緒后，方可澆注混凝土，且清孔后到澆注混凝土的時(shí)間間隔不大于30min；否則，應(yīng)重新清孔。管的規(guī)格為 D57 ，管長為樁長加 1 米，底部管口用 3mm 厚 A3 鋼板焊接封閉，沿管外圍滿焊，確保牢固嚴(yán)密，頂部管口用蓋子蓋緊，確保不進(jìn)水泥漿及雜物。鋼筋籠下到設(shè)計(jì)高程后，應(yīng)采取固定措施。 （見圖六） 導(dǎo)管內(nèi)壁和法蘭表面如粘附有灰漿和泥砂應(yīng)擦拭干凈。（ 2）灌注前，對孔底沉淀層厚度應(yīng)再進(jìn)行一次測定。導(dǎo)管提 升時(shí)應(yīng)保持軸線豎直和位置居中，逐步提升。其一般的施工過程是：平場地、鋪設(shè)工作平臺(tái)、安裝鉆機(jī)、壓套管、鉆進(jìn)成孔、安放鋼筋籠、防導(dǎo)管、澆注混凝土、拉拔套管、檢查成樁質(zhì)量。導(dǎo)管提漏有兩種原因： ，一般采用上下振擊法，使混凝土強(qiáng)行流出，但如此時(shí)導(dǎo)管埋深很少，極易提漏。 盡可能提高混凝土澆注速度：開始澆混凝土?xí)r盡量積累大量混凝土，產(chǎn)生極大的沖擊力可以克服泥漿阻力；快速連續(xù)澆注，使混凝土和泥漿一直保持流動(dòng)狀態(tài)，可防導(dǎo)管堵塞。（ 3）內(nèi)徑應(yīng)一致，其誤差應(yīng)小于 177。這說明了兩點(diǎn)，其一是小應(yīng)變檢測和實(shí)際是相吻合的，基本反映了工程的實(shí)際情況；其二證實(shí)了該樁鉆孔深度達(dá)到了設(shè)計(jì)深度 2lm ，只是在灌注第一盤砼時(shí)沒有封住導(dǎo)管，加上沉淀過快，導(dǎo)管在砼開盤前已經(jīng)被中粗砂礫淤埋，之后在操作導(dǎo)管時(shí)可能過提，沒有被及時(shí)發(fā)現(xiàn)或重視，導(dǎo)致該底樁在 3 米范圍內(nèi)混凝土沒有成型，發(fā)生斷樁。為了防止孔底周壁中粗砂的涌人，在壓漿前不能停止清孔。 注漿主要是通過擠密填充補(bǔ)強(qiáng)來保證樁體底部質(zhì)量。 造成原因： 孔壁坍陷的主要原因是土質(zhì)松散，泥漿護(hù)壁不好，護(hù)筒四周未用粘土緊密填封以及護(hù)筒內(nèi)水位不高。 當(dāng)碰到地下水流量大，護(hù)壁及下鋼護(hù)筒均不起作用時(shí)，可采用在本樁四周井點(diǎn)降水的方法，降低孔內(nèi)地下水位，直至砼澆注完畢。 鉆機(jī)就位時(shí)，應(yīng)使轉(zhuǎn)盤，底座水平，使天輪的輪緣、鉆桿的卡盤和護(hù)筒的中心在同一垂直線上，并在鉆進(jìn)過程中防止位移，在不均勻地層中鉆孔時(shí)，采用自重大、鉆桿剛度大的鉆機(jī)。若發(fā)生了這類事故，要對樁底的斷層位置、地質(zhì)、鉆孔成孔狀況及當(dāng)時(shí)原始記錄加以認(rèn)真分析，處理后必須要再進(jìn)行驗(yàn)證。 卡管 （ 1） 初灌時(shí)隔水栓卡管；或由于混凝土本身的原因，處理辦法可用長桿沖搗導(dǎo)管內(nèi)混凝土，用吊繩拌動(dòng)導(dǎo)管，或在導(dǎo)管上安裝附著式振搗器等使隔水栓下落。但這種樁也應(yīng)按斷樁采取補(bǔ)強(qiáng)處理。 鋼筋籠上升 造成原因： 當(dāng)混凝土灌注至鋼筋籠下，若此時(shí)提升導(dǎo)管，導(dǎo)管底端距離鋼筋籠僅有 1m 左右的距離時(shí)，由于澆注的混凝土自導(dǎo)管流出后沖擊力較大，推動(dòng)了鋼筋籠上浮。 灌注將近結(jié)束時(shí)，漿渣過稠；用測深錘深測難于判斷漿渣或混凝土面，或由于測深錘太輕，沉不到混凝土表面，發(fā)生誤測，拔除導(dǎo)管，中止灌注，而造成澆短樁頭事 24 故。只有從嚴(yán)把關(guān)，使一流人才、先進(jìn)的工藝，過硬的設(shè)備進(jìn)場，就為優(yōu)良工程打下了堅(jiān)實(shí)的物質(zhì)基礎(chǔ)。在此特向 所有指導(dǎo) 老師致以衷心的謝意！向 你們 無可挑剔的敬業(yè)精神、嚴(yán)謹(jǐn)認(rèn)真的治學(xué)態(tài)度、深厚的專業(yè)修養(yǎng)和平易近人的待人方式表示深深的敬意！ 最后，我要向百忙之中抽時(shí)間對本文進(jìn)行審閱，評議和參與本 人論文答辯的各位老師表示感謝。s performers of the troupe still tour the region39。s essay titled SelfReliance. If you39。s Liaoning province, decades ago. The solider gave the old man a handmade saddle when they bid farewell. The story inspired Nasun to write Carved Saddle, a song that later became one of his most popular numbers. Now, every year, Nasun recruits young singers and dancers for the troupe. The troupe has also designed a new repertoire, which is mostly based on the daily lives of Mongolian people, especially the lives of nomadic families, and has bined contemporary musical elements with folk songs of the region. Haimu, a 25yearold khoomei (a local variant of overtone singing) singer, joined the troupe three years ago. Along with a sixmember band, he performs fast songs and soft ones that he writes－ all while playing the horsehead fiddle.Although I learned the piano since childhood and grew up listening to various kinds of music, to me, the folk music of Inner Mongolia is the root, he says. Performing in remote villages is pleasant. I feel at home on the boundless grasslands, and the warm people there make me feel fulfilled. The first round of spring auction season in Beijing ended last week, but it failed to create much spring in the art market. Although two pieces of Chinese painting fetched more than 100 million yuan, the decline in trading volume and sa le rate showed a downturn this year. In the ―Grand View: Chinese Painting Highlight‖ session at China Guardian 2021 spring auctions, Pan Tianshou’s representative work Eagle, Rock and Flora hit a record auction price of 279 million yuan, while Li Keran’s masterwork Jinggang Mountain fetched million yuan, an unexpected high in recent years. However, the trading volume fells to billion yuan from billion yuan in the same period the year before. The Huangchen 2021 Spring Auctions, which recorded million yuan in total sales, experienced the same. The section number went down to 5 from 12 pared to last year. According to expert Shao Jianwu, the art market did not attract much excitement this year due to the booming stock market and the persistent problems of fery and fake deals. The two pieces of Chinese painting notched up high price this spring due to their own value not due to a revival in the market. The successful transaction of two works with a hammer price of more than 100 million yuan once again confirms that valuable and rare works of high quality always earn the longlasting high price. Chinese painting and calligraphy is still the pillar of the market. However, the overall sales rate has dropped slightly, which reflects the demand for the ordinary auction goods has weakened,‖ said the president of China Guardian’s Hu Yanyan. Besides, the entry of new buyers also makes certain changes to the direction of purchasing. In a word, the overall market trend is very unpredictable. Although China Guardian 2021 Spring Auctions has achieved remarkable results, it does not mean that the market has walked out of the predicament. We still have to wait for the big economic boom to invigorate the art market.‖ Even so, the hot pursuit of some special items appeared this spring. A special session of China Guardian Spring Auctions titled ―Fine Gilt—Bronze Buddhist Images‖ achieved a great deal with total sales volume of million yuan and 92 percent sale rate. The 5th Shamar Rinpoche Statue from 1617th century of Tibet was sold for million yuan. The Beijing Chengxuan Auctions featured almost 2,800 items of coins and stamps in thre