1221166 玖、發明說明 【發明所屬之技術領域】 本發明係有關於將例如湖沼周圍之人造陸地區域等之 軟弱地盤中所含有的大量水分加以排出，藉此將軟弱地盤 改良成硬質地盤之改良工法及改良裝置。詳細說明的話， 係有關於利用與真空壓力傳送路徑彼此獨立之排水路徑， 將間隙水自改良地盤加以排出，藉此將改良地盤內之真空 壓力傳達到改良地盤內之各角落，而能夠更有效率地將地 盤加以改良的軟弱地盤改良工法及改良裝置。 【先前技術】 先前的軟弱地盤改良裝置，如日本之發明專利申請案 之平成11年第131465號公開公報所示，透過在改良地盤 中間隔既定距離設置之垂直排水材，將真空壓力施加在改 良地盤中，藉此在前述改良地盤中作出與改良地盤周邊部 隔離的減壓區域。 第11圖所示之改良裝置，具有：垂直排水材1，在改 良地盤A中間隔既定距離設置；水平排水材2，配置成接 觸前述各垂直排水材1之上端部；集水管3，連接到前述水 平排水材2 ;氣密片6，將改良地盤A上面，與前述垂直排 水材1、水平排水材2及集水管3 —起被覆；及真空泵5， 透過真空槽4連接於前述集水管3。 使用第11圖所示裝置之改良工法如下。亦即，使真空 泵5運作，當真空槽4由於來自前述真空泵5的真空壓力 而達到既定的減壓度時，減壓止回閥（未圖示）會打開，使連 5 1221166 接於該減壓止回閥之集水管3減壓。接著，真空壓力會在 連接於前述集水管3之水平排水材2傳送，使水平排水材2 減壓。又，真空壓力會在上端部連接於前述水平排水材2 之垂直排水材1，使垂直排水材1內部達到既定減壓度（0.4 大氣壓以下）。 又，垂直排水材1內之真空壓力，傳送到垂直排水材1 周圍之地盤A，將以垂直排水材1爲中心之周圍地盤，當 作減壓狀態區域（以下稱做「減壓區域」）。 真空壓力自變成減壓區域之垂直排水材1周圍地盤， 更加往外側周圍地盤傳送，結果，產生朝向垂直排水材1 之地盤加壓（水壓、土壓）。 隨著前述地盤加壓，包含在垂直排水材1周圍地盤中 之間隙水往垂直排水材1被吸出，並以垂直排水材1、水平 排水材2及集水管3爲排水路徑排出，垂直排水材1周圍 地盤之更外側周圍藉此也變成減壓區域。 如此一來，減壓區域以垂直排水材1爲中心，擴大到 其周圍地盤，不久，改良地盤A全區域都變成減壓區域， 同時，以垂直排水材1爲中心，進行著壓密和強度增加， 使改良地盤A全區域都實施壓密和強度增加。 【發明內容】 (一）發明所欲解決之技術問題 可是，在前述改良裝置中，作爲來自真空栗5之真空 壓力傳送路徑的真空泵5、真空槽4、集水管3、水平排水 材2及垂直排水材1，同樣成爲自改良地盤被吸出之間隙水 6 1221166 的排水路徑。 因此，如果使用此改良裝置的話，在傳送真空壓力之 初，在集水管2內，間隙水通過垂直排水材1及水平排水 材2,自改良地盤A —下子大量流入並充滿前述集水管3 內，來自真空泵4之真空壓力或者無法傳達到垂直排水材1 ，或者難以傳達到垂直排水材1，嚴重妨礙改良效率。 又，前述改良裝置中，作爲來自真空栗5之真空壓力 傳送路徑的真空泵5、真空槽4、集水管3、水平排水材2 及垂直排水材1，同樣成爲自改良地盤被吸出之間隙水的排 β 水路徑，所以，隨著地盤下陷，真空泵5會產生抽水壓損 失。 (二）解決問題之技術手段 本發明係鑒於前述缺點而產生之工法及裝置。本發明 之目的，係提供一種軟弱地盤改良工法及改良裝置，藉由 與真空壓力傳送路徑各自獨立之排水路徑，將間隙水自改 良地盤排出，藉此使改良地盤內之真空壓力傳達到改良地 盤內各個角落，能夠效率更佳地將地盤加以改良。 亦即，第1發明的軟弱地盤改良工法之特徵，係以氣 密片被覆改良地盤上面，使真空壓力在前述改良地盤中傳 送，藉此在前述改良地盤中作出與改良地盤周邊部隔離的 減壓區域；其特徵在於：使隨著前述真空壓力之傳送，而 自改良地盤內吸出之間隙水，經由與前述真空壓力傳送路 徑各自獨立之排水路徑排出。 第2發明的軟弱地盤改良裝置之特徵，係以氣密片被 7 1221166 覆改良地盤上面，使真空壓力在前述改良地盤中傳送，藉 此在前述改良地盤中作出與改良地盤周邊部隔離的減壓區 域；其特徵在於：具有排水路徑，而前述排水路徑係與將 前述真空壓力傳送到前述改良地盤之真空壓力傳送路徑各 自獨立。 【實施方式】 以下，以圖面所示之一實施例，詳細說明本發明之軟 弱地盤改良工法及改良裝置。第1圖所示之改良裝置，係 藉由將真空壓力傳送到改良地盤A中’在則述改良地盤A 0 中，作出與改良地盤周邊部B隔離之減壓區域，該改良裝 置具有將真空壓力產生機構所產生之真空壓力傳送到改良 地盤A的真空壓力傳送路徑，以及與前述真空壓力傳送路 徑各自獨立的間隙水之排水路徑。 第1圖所示改良裝置之真空壓力傳送路徑係包括：垂 直排水材11，在改良地盤A中間隔既定距離設置；水平排 水材12，與前述各垂直排水材11相連接；集水管13，連 接到水平排水材12 ;以及真空泵15，透過真空槽14連接 * 於前述集水管13。 垂直排水材11，只要是在負載的環境下也能確保作爲 真空壓力（減壓）之傳送和排水路徑之功能，不會堵塞，不會 因爲下陷所產生之壓縮或減壓而壓壞的話，其構造、素材 和大小都可以隨意設計。第1圖所示之垂直排水材Π，係 使用由合成樹脂網及包裹前述合成樹脂網的不織布所構成 者；該合成樹脂網，係在長度方向間隔一定距離立設排列 8 1221166 之長形平板狀合成樹脂線材上，沿正交方向間隔既定距離 立設排列同樣長形之平板狀合成樹脂線材’並將該等合成 樹脂線材在交點接合而成。前述垂直排水材11，即使被彎 折也能夠確保由合成樹脂網和不織布所構成的通水路徑’ 而且，合成樹脂網全體係被不織布所覆盡’具有不易堵塞 的優點。將前述垂直排水材11間隔既定距離打設於地盤， 並且使其上端部留在地盤外，藉此在改良地盤A中作出垂 直排水壁。 水平排水材12係被配置成接觸前述垂直排水材11留 _ 在改良地盤A上面之上端部。水平排水材12 ’只要是能夠 具有使水及空氣在前述水平排水材12長度方向（水平方向） 上能移動的通路功能的話’可以是線狀、帶狀或面狀’但 是，前述水平排水材12其透過前述垂直排水材11自改良 地盤A側吸起之水及空氣所進入之入口（例如孔或狹縫）最 好是，不大會被地盤中之砂、砂土等所堵塞’而使水及空 氣容易進入水平排水材12內部之構造’或者是通路不大會 被改良地盤A中之砂或砂土等所堵塞而使水及空氣可移動 β 之構造。在第1圖所示之實施例中’係使用與前述垂直排 水材11相同構造（由合成樹脂網及覆蓋合成樹脂網表面的 不織布所構成）。在此狀況下，水及空氣自覆蓋合成樹脂網 的不織布側進入，通過合成樹脂網和不織布之間隙，以及 構成不織布之纖維間而移動。 在前述水平排水材12之必要處連接有集水管13。集水 管13係在管周面設有多數孔的有孔管（圖例中爲PVC管）， 9 1221166 於前述集水管13之一端側透過配置於改良地盤A外（工地 外）之真空槽14連接真空泵15。 產生真空壓力而作爲真空產生機構之真空泵15並沒有 特別限定，只要是考慮到改良地盤規模或所要求的真空壓 力大小而選定之裝置就可以。第1圖之真空泵15係採用水 密式真空泵。 改良地盤A上面，與前述垂直排水材11上端部、水平 排水材12及集水管13都以氣密片10覆蓋，藉此，真空泵 15所產生之真空壓力，透過真空槽14、集水管13、水平排 · 水材12及垂直排水材11，能夠確實地傳送到改良地盤A 上面及改良地盤A內部。而且，在第1圖所示之氣密片10 ，係使用在不織布或織物等纖維基材上積層合成樹脂膜而 成之防針孔者。 另外，第1圖所示改良裝置之排水路徑，係具有配置 在集水管13下側改良地盤A內，而且通到改良地盤A外部 之排水槽16。前述排水槽16透過分離器17連接到集水管 13下側之改良地盤內。而且，集中在集水管13之自改良地 * 盤A吸出之間隙水，藉由分離器17而與空氣分離，利用重 力流入集水管13下側排水槽16內，儲存在排水槽16中。 如第1圖所示，在排水槽16內部內藏有排水泵18，儲 存在排水槽16內部之水經由透過連結管19連接於前述排 水槽16之排水管20，被強制排出改良地盤A外。 而且，排水槽16之形狀或尺寸可以任意設計，只要考 慮到改良地盤規模或地盤種類等即可。又，內藏於排水槽 10 1221166 16內之排水泵18的種類可以爲任意型式，只要考慮到改良 地盤規模、地盤種類或價格即可。 另，在排水槽16中，也可以設置將流入槽中之間隙水 水量加以測定的測定裝置。復’也可以在排水槽16設置水 位檢出裝置，附加使排水泵18能夠自動運轉之控制裝置。 又，連結管19及排水管20，係將自改良地盤A吸出 之間隙水排到改良地盤A外（亦即’工地外）之導管’其設 置位置可以爲任意處所’但是’最好比前述集水管13還要 下側。又，連結管19及排水管20 口徑愈大’雖然排水效 · 率會變高，但是，設置作業會變困難，所以，要考慮到改 良地盤規模或地盤種類而適當決定。 而且，在第1圖所示之實施例中，爲了防止自地盤排 出之間隙水逆流，在連結管19及排水管20中設有止回閥 2卜 利用如此構成的第1圖改良裝置的話，隨著真空壓力 負荷而自改良地盤A內吸出之空氣及間隙水的大部分，係 經由與前述真空壓力傳送路徑各自獨立之排水路徑（亦即，* 配置在集水管13下側改良地盤A內之排水槽16、連結管 19及排水管20)被排出改良地盤A外。 另外，自改良地盤A來的空氣及間隙水之一部分，係 透過真空壓力傳送路徑之垂直排水材11、水平排水材12及 連接前述各排水材之集水管13，被排到真空槽14內，此間 隙水藉由配置於前述真空槽14內之排水泵18被排出改良 地盤A(裝置）外，空氣則藉由真空泵15被排出改良地盤A( 11 1221166 裝置）外。 而且，當作爲真空壓力產生機構之真空泵14,使用水 密式真空泵時，最好採用具備第2圖所示之水封用循環冷 卻水槽30之真空槽14。當使用水密式真空泵時，必須要供 給水封用冷卻水到前述水密式真空泵。可是如前所述，利 用本發明之改良裝置的話，因爲隨著真空壓力負荷而自改 良地盤A內吸出之空氣及間隙水的大部分，係經由與前述 真空壓力傳送路徑各自獨立之排水路徑（亦即，配置在集水 管13下側改良地盤A內之排水槽16、連結管19及排水管 ® 20)被排出改良地盤A外，所以，通過真空壓力傳送路徑被 排到真空槽14內之空氣及間隙水非常少量。 因此，當隨著地盤改良而間隙水量減少時，當然，排 到真空槽14內之間隙水量也會減少，而無法供給水封用間 隙水到真空泵15，此時，會產生真空泵15之效率會逐漸降 低之缺點。 如果使用第2圖所示之真空泵15的話，因爲具備有水 封用循環冷卻水槽30，水封用循環冷卻水通過冷卻水循環 * 用泵32被供給到真空泵15，所以，真空泵15能夠經常確 保充分的水密性，真空泵15的效率也就不會逐漸降低。又 ，在真空槽14之冷卻水循環路徑中，配置有冷卻用冷凝器 31，將冷卻水在循環過程中加以冷卻。 又，在第2圖所示之真空槽14底部連接有排水管20 前端，自改良地盤A來之間隙水係排出到真空槽14中。自 改良地盤A來的間隙水水溫很低，所以，排到真空槽14內 12 1221166 之間隙水可以當作真空杲15之冷卻水使用，真空槽14內 用於將冷卻水加以冷卻的冷卻用冷凝器31，基本上並不需 要，而能夠減少冷卻用冷凝器31之使用。 又，在本發明改良裝置中，也能夠設置將大氣或壓縮 空氣送入改良地盤A及/或改良地盤周邊部B內之通氣路徑 。第3圖所示改良裝置中，在改良地盤A(表層部分或地盤 內部）之複數處設有排水管40。排水管40 —端透過地上的 集水管43、鼓風機41及空氣量之控制機構42，連接到外 部大氣；真空壓力（例如0.4大氣壓以下）被控制在既定範圍 · 內之壓縮空氣被送入改良地盤A中，該真空壓是透過前述 排水管40、集水管43、鼓風機41及控制機構42而傳送到 改良地盤A。 藉此，配置有排水管40之改良地盤A(表層部分或地盤 內部）中之間隙水，與被送入之空氣置換而水位降低，促進 改良地盤A之塑性化和不飽和化。又，藉由導入空氣，下 陷變形變少之改良地盤A真空區域處之壓力變不平衡，促 進強制排水，所以，更有效地提高地盤改良效果。 * 而且，第3圖所示之改良裝置中，送入改良地盤A中 之壓縮空氣可以連續或間歇地送入。而且，在第3圖之實 施例中，使用具有鼓風機41之排水管40，將壓縮空氣強制 送入改良地盤A中，但是，並不侷限於此，僅單獨將排水 管40配置於改良地盤A中，使空氣洩漏也可以。 第4圖所示之改良裝置中，在改良地盤周邊部B中之 複數處配置（最好是在離開改良地盤A數公尺以內處，以間 13 隔0.3〜1公尺，配置1列以上）排水管40。又，將各排水管 40連接到在端部具有閥（未圖示）之集水管43，藉由前述閥( 未圖示）之開閉，使改良地盤周邊部B內部和外部大氣相連 通。而且，排水管40上端和集水管43係用黏土回塡，確 保氣密性。 因此，配置有排水管40之改良地盤周邊部B中之間隙 水，藉由閥（未圖示）之開閉，透過各排水管40及集水管43 而與洩漏的空氣對調而蒸發，改良地盤周邊部B之地下水 會降低，會促進改良地盤周邊部B特別是表層部之塑性化 和不飽和化，使其更加硬化。結果，在改良地盤A和改良 地盤周邊部B間會產生切邊效果，而緩和地盤改良對改良 地盤周邊部B之影響，只有改良地盤A會下陷。 第5圖所示之改良裝置中，與在改良地盤A中間隔既 定距離設置之各垂直排水材51透過水平排水材52來連接 之集水管53集水路徑必要位置上，連接有複數個第1排水 槽54(參照第6圖）。集水管53連接到第1排水槽54之上部 位置，集中在前述集水管53之間隙水被排到前述各第1排 水槽54。 而且，關於第5圖所示之改良裝置，與第1圖所示裝 置相同地，改良地盤上面與垂直排水材51上端部、水平排 水材52及集水管53均被氣密片50所覆蓋，真空泵（未圖示 )所產生之真空壓力，透過真空槽（未圖示）、集水管53、水 平排水材52及垂直排水材51，確實地傳送到改良地盤A 上面以及改良地盤A內部。 14 1221166 前述裝置又具有通往連接於集水管53集水路徑必要位 置之改良地盤A外（亦即，工地外）之第2排水槽55(參照第 7圖）；在前述第2排水槽55和第1排水槽54之間，以及 前述第1排水槽54之間，藉由連接到第1排水槽54及第2 排水槽55下部之連通管56而呈連通狀態。 往各第1排水槽54排出之間隙水，係透過前述連通管 56往第2排水槽55排出。第2排水槽55內之間隙水，藉 由內藏於第2排水槽55內部之排水泵57，通過排水管58 被強制排出。而且，爲了防止間隙水逆流，在排水管58上 β 設有止回閥59。 另外，藉由集水管13而與間隙水一起被輸送到第2排 水槽55內之空氣，通過連接到真空槽14之排氣管60排出 〇 接著，針對第8〜10圖所示之改良裝置加以說明。第 8〜10圖所示之改良裝置中，水平排水材72和集水管73皆 具有傳送真空壓力的傳送構造及將間隙水排出之排水構造 ，並與排水槽一起構成排水路徑，前述排水路徑係與真空 * 壓力傳送路徑各自獨立。 亦即，水平排水材72具有使空氣和水在前述水平排水 材72長度方向（水平方向）上移動之2個通路（真空壓力傳送 路徑和排水路徑）。第8圖所示之實施例中，使用與前述垂 直排水材71相同構造（由合成樹脂網和覆蓋合成樹脂網之 不織布所構成），將其在長度方向上摺成兩折，其內側夾住 垂直排水材71上端部，藉此連接於垂直排水材71。 15 1221166 前述水平排水材72下側之折片部72a成爲間隙水之排 水路徑，上側之折片部72b成爲真空壓力之傳送路徑。而 且，通過垂直排水材71自改良地盤吸出之間隙水，因爲重 力會流入水平排水材72下側之折片部72a，以此爲排水路 徑，沿著水平排水材72移動，往集水管73排出。 另外，真空泵（未圖示）產生之真空壓力（空氣）輕，所以 ，以水平排水材72上側折片部72b爲傳送路徑，沿著水平 排水材72移動而往垂直排水材71傳送。 集水管73也與水平排水材72同樣地，具有真空壓力鲁 傳送構造和排出間隙水的排水構造。第9圖所示者，係在 管周面設有多數孔的有孔管（圖中所示爲PVC管），管內部 設有將管上下隔開而且具有穿孔的隔牆73a，前述隔牆73a 上側係真空壓力傳送路徑’而前述隔牆73a下側則成爲間 隙水之排水路徑。又’弟1 〇圖所不者，係在隔牆7 3 a之穿 孔設置止回閥73b，防止因爲重力而流入隔牆73a下側之間 隙水往隔牆73a上側逆流。 第8〜10圖所示之改良裝置中，水平排水材72及集水 ® 管73，皆具有真空壓力傳送構造和排出間隙水的排水構造 ，所以，與排水槽一起構成與真空壓力傳送路徑各自獨立 的排水路徑，而能夠更有效率地將間隙水排出。 接著，針對本發明之軟弱地盤改良工法（以下’簡稱爲 「改良工法」）加以說明。第1圖所示裝置所使用之改良工 法如下。首先，將垂直排水材11以既定間隔打設在改良地 盤A中。打設垂直排水材11之間隔，最好是所施加真空壓 16 1221166 力所能傳送到的範圍，具體來說，係1公尺左右。前述垂 直排水材11之打設，係將垂直排水材11在插入心軸內部（ 未圖示）之狀態下貫入改良地盤A中，在垂直排水材11留 在改良地盤A中之下將心軸（未圖示）取回。 如此一來，藉由將垂直排水材11間隔既定距離打設於 改良地盤A中，在改良地盤A中會形成間隔既定距離之垂 直狀排水柱，通過構成這些排水柱之垂直排水材11，真空 泵15所產生之真空壓力會傳送到改良地盤A中，同時，包 含於各排水柱間之改良地盤A中的水及空氣，也以垂直排 β 水材11爲排水路徑被吸起。 在該垂直排水材11上，連接有水平排水材12。垂直排 水材11被打入改良地盤A中而其上端部11a則突出改良地 盤A上面，將水平排水材12以接觸前述突出部11a之方式 平行配置。 將集水管13連接於前述水平排水材12之必要處。集 水管13係在管周面設有多數孔之有孔管’前述集水管13 一端側係透過配置於改良地盤A外（亦即，工地外）之真空 槽14而連接到真空泵15。而且，真空泵15所產生之真空 壓力透過真空槽14被傳達到集水管13,又’真空壓力透過 連接到前述集水管13之水平排水材12及垂直排水材11 ’ 而傳送到改良地盤A。 而且，在本發明之改良工法中，在打設垂直排水材11 、配置水平排水材12及連接集水管之後’將改良地盤A上 面，與垂直排水材Η上端部、水平排水材12及集水管13 17 1221166 一起以氣密片10覆蓋，以使真空泵15所產生之真空壓力 能夠確實地傳送到改良地盤A上面及改良地盤內部。 如此一來，使用第1圖所示改良裝置之改良工法中， 真空泵15所產生之真空壓力傳送到真空槽14、集水管13 、水平排水材12及垂直排水材11，使垂直排水材11內達 到既定的減壓度（0.4大氣壓以下）。 又，垂直排水材11內之真空壓力，傳送到垂直排水材 11周圍的地盤A，以垂直排水材11爲中心的周圍地盤A都 成爲減壓狀態的區域（以下簡稱爲「減壓區域」）。 真空壓力係自成爲減壓區域的垂直排水材11周圍的地 盤A，再往周圍的地盤A傳送而去，會發生朝向垂直排水 材11周圍地盤A之地盤加壓（水壓、土壓）。 隨著前述地盤加壓，包含於垂直排水材11周圍地盤A 之間隙水，朝向垂直排水材11被吸出，通過垂直排水材11 、水平排水材12及集水管13排出，而垂直排水材11周圍 地盤A之外側也變成減壓區域。 如此一來，減壓區域會以垂直排水材11爲中心，擴大 到其周圍之地盤A，不久，改良地盤A全區都會變成減壓 區域，同時，以垂直排水材11爲中心之壓密及強度增加都 會進行，而實施改良地盤A全區之壓密及強度增加。 另外，自改良地盤A吸出之間隙水，通過以下之排水 路徑被排出。亦即，通過垂直排水材11及水平排水材12 被吸出改良地盤A之間隙水，暫時流入集水管13內。 如第1圖所示，集水管13下側之改良地盤A內透過分 18 1221166 離器17連接有排水槽16。集中在集水管13之間隙水，藉 由分離器Π而與空氣分離，利用重力流入集水管13下側 排水槽16內，儲存在排水槽16中。 隨著改良地盤Α中間隙水之排出，地盤Α產生壓密下 陷。當地盤A下陷時，設於地表之真空槽14和設於地盤A 中之排水槽16之間會產生高度差。當前述高度差超過10 公尺時，若利用前述真空壓力之排水方法，就無法將地盤 A中之間隙水排出。原因在於，1大氣壓下之真空抽水力的 極限在10公尺。因此，地盤A愈下陷，真空泵15之真空 ® 抽水力就愈低，排水效率也變低。 第1圖所示之排水槽16中內藏有排水泵18，將儲存在 排水槽16內之間隙水，透過排水管20(透過連結管19連接 於前述排水槽16)，被強制排出改良地盤A外（亦即，工地 外）。因此，排水不受地盤A下陷之影響，地盤深部之改良 也能夠更加有效率而確實地實施。而且，排水槽16之設置 位置，只要是在集水管13下側，以使集水管13內之水因 爲重力而流入就可以。 * 又，當使用內藏有排水泵18之排水槽16時，因爲地 盤A之下陷不影響排水，所以，藉由真空壓力在地盤A中 作出減壓區域後，如果繼續施加真空壓力的話，改良地盤 中特別是地盤表層部（自地表起到1〜2公尺深度）所含之水分 會蒸發，地盤變成不飽和土。所謂「不飽和土」，係不會 發生因爲土堆等之下壓負荷而產生過剩間隙水壓，材質比 飽和土還要強。因此，即使作出減壓區域後，再繼續施加 19 1221166 真空壓力之地盤，特別是地盤表層部之不飽和化，比起在 地盤改良中或地盤改良後再堆土之情形，土堆崩塌的危險 會大幅地減少。 又，當使用內藏有排水泵18之排水槽16時，與地盤 改良程度無關地能夠傳送真空壓力，所以，若在地盤不飽 和化之後持續施加真空壓力的話，地盤中之水分會進一步 被除去，地盤就由不飽和狀態，變成非常堅硬而且穩定的 塑性化狀態。 而且，在圖面所示之實施例中，在排水槽16中內藏有 0 排水泵18，將儲存在排水槽16內之水強制排出裝置外，但 是，因爲改良地盤規模或地盤種類，有時也能夠使用沒有 內藏排水泵18的排水槽16。 而且，在圖面所示之實施例中，雖然藉由真空泵15所 產生之真空壓力使垂直排水材11內部達到0.4大氣壓以下 ，但是，並不侷限於此，可以考慮改良地盤的軟弱程度， 例如地盤含水率等，而適當決定真空壓力的大小。 在使用第5〜7圖所示改良裝置之改良工法中，在與在 * 改良地盤A中間隔既定距離設置之各垂直排水材51透過水 平排水材52來連接之集水管53集水路徑中，連接有複數 個第1排水槽54及通到前述改良地盤外之第2排水槽55， 同時，前述第1排水槽54和第2排水槽55係藉由連通管 56相連通，將集中於前述集水管13之間隙水排到前述第1 排水槽54，再將前述第1排水槽54內之間隙水排到第2排 水槽55，藉由內藏於前述第2排水槽55內部之排水泵57 20 ，將前述第2排水槽55內之間隙水強制排出。 在使用第8〜10圖所示改良裝置之改良工法中，水平排 水材72及集水管73皆具有傳送真空壓力之傳送構造和排 出間隙水之排水構造，所以，通過垂直排水材自改良地盤 A內吸出之間隙水，通過前述水平排水材72及集水管73 上分別設置與真空壓力傳送構造各自獨立的間隙水排水構 造，流入配置在集水管73下側改良地盤內之排水槽，排出 改良地盤外（亦即，工地外）。 而且，上述實施例只不過是說明例，例如使施加在地 盤中之真空壓力，在改良之初施以高真空壓力，之後維持 低真空壓力，或者，使高低真空壓力交替反覆等，在申請 專利範圍之項目中所記載的範圍之內可以自由變更。 【發明效果】 在本發明之本工法中，與在改良地盤中間隔既定距離 設置之各垂直排水材透過水平排水材來連接之集水管下側 之改良地盤內配置排水槽，而將集中於集水管之間隙水排 到排水槽，接著，使前述排水槽內之間隙水，通過連接到 前述排水槽之排水管’將水排到改良地盤外，利用與傳送 真空壓力之傳送路徑不同之路徑’將改良地盤中之間隙水 排出，所以，能夠更有效率地將地盤加以改良。 特別是，當將排水泵內藏於排水槽內，將前述排水槽 內之間隙水強制排出改良地盤外時’不受地盤下陷影響而 能夠繼續排水，所以，在地盤下陷時，也不會產生真空壓 力之抽水壓損失。又’藉由真空壓力在地盤中作出減壓區 21 1221166 域之後繼續施加真空壓力的話，改良地盤，特別是地盤表 層部（自地表起1〜2公尺深）所含之水分會蒸發，地盤會變成 不飽和土。 又，若在地盤不飽和化之後持續施加真空壓力的話， 地盤中之水分會進一步被除去，能夠由不飽和狀態，改良 成非常堅硬而且穩定的塑性化地盤。 又，本發明之改良裝置，具備：在改良地盤中間隔既 定距離設置之垂直排水材、透過水平排水材連結於前述各 垂直排水材的集水管、及配置在前述集水管下側改良地盤 β 內而通到改良地盤外之排水槽，利用與傳送真空壓力到改 良地盤之傳送路徑不同的路徑，將來自改良地盤的間隙水 加以排出，所以，能夠更有效率地將地盤加以改良。 特別是，當排水槽內藏有排水泵時，能夠將前述排水 槽內的間隙水經由排水管強制排出，而且不受地盤下陷影 響，能夠持續排水，所以，藉由真空壓力在地盤中作出減 壓區域之後繼續施加真空壓力的話，改良地盤，特別是地 盤表層部（自地表起1〜2公尺深）所含之水分會蒸發，地盤會鲁 變成不飽和土。 又，如果在地盤不飽和化之後持續施加真空壓力的話 ’地盤中之水分會進一步被除去，能夠由不飽和狀態，改 良成非常堅硬而且穩定的塑性化地盤。 【圖式簡單說明】 (一）圖式部分 弟1圖係表不本發明改良裝置之示意圖。 22 1221166 第2圖係表示本發明改良裝置水封用循環冷卻水槽之 放大示意圖。 第3圖係表示本發明改良裝置另一實施例之示意圖。 第4圖係表示本發明改良裝置又一實施例之示意圖。 第5圖係表示本發明改良裝置又一實施例之示意圖。 第6圖係表示第5圖所示實施例中第1排水槽之放大 立體圖。 第7圖係表示第5圖所示實施例中第2排水槽之放大 立體圖。 第8圖係表示本發明改良裝置另一實施例之示意圖。 第9圖係表示本發明改良裝置又一實施例之示意圖。 第10圖係表示本發明改良裝置又一實施例之示意圖。 第11圖係表示習知改良裝置之示意圖。 (二）元件代表符號 1 垂直排水材 2 水平排水材 3 集水管 4 真空槽 5 真空泵 6 氣密片 10 氣密片 11 垂直排水材 12 水平排水材 13 集水管 23 1221166 14 真空槽 15 真空泵 16 排水槽 17 分離器 18 排水泵 19 連結管 20 排水管 21 止回閥 30 水封用循環冷卻水槽 31 冷卻用冷凝器 32 冷卻水循環用管 40 排水管 41 鼓風機 42 控制機構 43 集水管 50 氣密片 51 垂直排水材 52 水平排水材 53 集水管 54 第1排水槽 55 第2排水槽 56 連通管 57 排水泵 58 排水管1221166 发明 Description of the invention [Technical field to which the invention belongs] The present invention relates to an improvement method for draining a large amount of water contained in a soft ground such as an artificial land area around a lake or marsh, thereby improving a weak ground into a hard ground And improved devices. In detail, it is related to the use of a drainage path that is independent of the vacuum pressure transmission path to discharge the gap water from the improved site, thereby transmitting the vacuum pressure in the improved site to all corners in the improved site, so that it can be more Weak site improvement method and device for efficiently improving the site. [Prior art] A conventional weak site improvement device, as shown in Japanese Patent Publication No. 131465 of Heisei 11 of the Japanese Patent Application for Invention, applies a vacuum pressure to the improvement through vertical drainage materials arranged at a predetermined distance in the improved site. In a construction site, a decompression area isolated from a peripheral portion of the improved construction site is thereby created in the improved construction site. The improved device shown in FIG. 11 includes: a vertical drainage material 1 arranged at a predetermined distance in the improved site A; a horizontal drainage material 2 arranged to contact the upper end of each of the vertical drainage materials 1; and a water collecting pipe 3 connected to The aforementioned horizontal drainage material 2; the airtight sheet 6 covers the upper surface of the improved site A with the aforementioned vertical drainage material 1, the horizontal drainage material 2 and the water collecting pipe 3; and the vacuum pump 5 is connected to the water collecting pipe 3 through the vacuum tank 4 . The modified method using the device shown in Fig. 11 is as follows. That is, the vacuum pump 5 is operated. When the vacuum tank 4 reaches a predetermined pressure reduction degree due to the vacuum pressure from the vacuum pump 5 described above, the pressure reduction check valve (not shown) will be opened, so that 5 1221166 is connected to the pressure reduction. The water collecting pipe 3 which presses the check valve is decompressed. Then, the vacuum pressure is transmitted to the horizontal drainage material 2 connected to the aforementioned water collecting pipe 3, so that the horizontal drainage material 2 is decompressed. In addition, the vacuum pressure is connected to the vertical drainage material 1 of the horizontal drainage material 2 at the upper end, so that the inside of the vertical drainage material 1 reaches a predetermined decompression degree (less than 0.4 atmospheres). In addition, the vacuum pressure in the vertical drainage material 1 is transmitted to the site A around the vertical drainage material 1, and the surrounding site with the vertical drainage material 1 as the center is regarded as a decompression state area (hereinafter referred to as "decompression area"). . The vacuum pressure changes from the site surrounding the vertical drainage material 1 to the decompression area, and is transmitted to the outer periphery. As a result, pressure (water pressure, earth pressure) is generated toward the site of the vertical drainage material 1. As the aforementioned site is pressurized, the clearance water contained in the site around the vertical drainage material 1 is sucked out to the vertical drainage material 1 and discharged through the vertical drainage material 1, the horizontal drainage material 2 and the water collecting pipe 3 as drainage paths. The vertical drainage material 1 The outer periphery of the surrounding site also becomes a decompression area. In this way, the decompression area is expanded to the surrounding site with the vertical drainage material 1 as the center. Soon, the entire area of the improved site A will become a decompression area. At the same time, the vertical drainage material 1 will be used as the center for compaction and strength. The increase makes compaction and strength increase in the entire area of the improved site A. [Summary of the Invention] (1) The technical problem to be solved by the invention, however, in the aforementioned improved device, the vacuum pump 5, the vacuum tank 4, the water collecting pipe 3, the horizontal drainage material 2 and the vertical are used as the vacuum pressure transmission path from the vacuum pump 5. The drainage material 1 also becomes a drainage path of the gap water 6 1221166 sucked from the improved construction site. Therefore, if this improved device is used, at the beginning of transmitting the vacuum pressure, the clearance water in the water collecting pipe 2 passes through the vertical drainage material 1 and the horizontal drainage material 2 to flow from the improved site A — the lower part flows into the water collecting tube 3 and fills it. The vacuum pressure from the vacuum pump 4 cannot be transmitted to the vertical drainage material 1 or is difficult to be transmitted to the vertical drainage material 1, which seriously hinders the improvement efficiency. In the aforementioned improved device, the vacuum pump 5, the vacuum tank 4, the water collecting pipe 3, the horizontal drainage material 2, and the vertical drainage material 1 as the vacuum pressure transmission path from the vacuum pump 5 also become the gap water sucked from the improved construction site. The β water path is discharged, so as the site subsides, the vacuum pump 5 will generate a pumping pressure loss. (II) Technical means for solving the problem The present invention is a method and a device for the above-mentioned disadvantages. The object of the present invention is to provide a weak site improvement method and an improvement device, which discharge gap water from the improved site through a drainage path independent of the vacuum pressure transmission path, thereby transmitting the vacuum pressure in the improved site to the improved site. Every corner of the interior can improve the site more efficiently. That is, the characteristic of the weak site improvement method of the first invention is that the improved site is covered with an airtight sheet, and the vacuum pressure is transmitted in the aforementioned improved site, thereby reducing the isolation from the periphery of the improved site in the aforementioned improved site. The pressure region is characterized in that the gap water sucked out of the improved construction site as the vacuum pressure is transmitted is discharged through a drainage path that is independent of the vacuum pressure transmission path. A feature of the weak site improvement device of the second invention is that an airtight sheet is used to cover the improved site by 7 1221166, so that the vacuum pressure is transmitted in the improved site, thereby reducing the isolation from the periphery of the improved site in the improved site. Pressure region; characterized in that it has a drainage path, and the drainage path is independent of the vacuum pressure transmission path that transmits the vacuum pressure to the improved site. [Embodiment] Hereinafter, an embodiment shown in the drawings will be used to describe in detail the weak site improvement method and the improvement device of the present invention. The improved device shown in FIG. 1 is a pressure reduction area isolated from the peripheral portion B of the improved site by transmitting vacuum pressure to the improved site A. In the improved site A 0, the improved unit includes a vacuum The vacuum pressure generated by the pressure generating mechanism is transmitted to the vacuum pressure transmission path of the improved site A, and the drainage path of the gap water which is independent of the vacuum pressure transmission path. The vacuum pressure transmission path of the improved device shown in FIG. 1 includes: vertical drainage materials 11 arranged at a predetermined distance in the improved site A; horizontal drainage materials 12 connected to the aforementioned vertical drainage materials 11; and water collecting pipes 13 connected To the horizontal drainage material 12; and the vacuum pump 15 connected to the aforementioned water collecting pipe 13 through the vacuum tank 14. As long as the vertical drainage material 11 can ensure the function of transmission and drainage path of vacuum pressure (decompression) under the load environment, it will not be blocked, and will not be crushed due to compression or decompression caused by depression. Its structure, material and size can be designed at will. The vertical drainage material Π shown in FIG. 1 is composed of a synthetic resin net and a non-woven fabric surrounding the aforementioned synthetic resin net. The synthetic resin net is a long flat plate arranged in a row at a distance of 8 1221166 at a certain distance in the longitudinal direction. The synthetic resin wire rods are formed by arranging flat synthetic resin wire rods of the same length at a predetermined distance in the orthogonal direction and joining the synthetic resin wire rods at intersections. Even if the vertical drainage material 11 is bent, it is possible to ensure a water passing path composed of a synthetic resin net and a nonwoven fabric. Further, the entire synthetic resin net system is covered by the nonwoven fabric. The vertical drainage material 11 is placed on the construction site at a predetermined distance and the upper end portion is left outside the construction site, thereby forming a vertical drainage wall in the improved construction site A. The horizontal drainage material 12 is arranged so as to contact the aforementioned vertical drainage material 11 to stay on the upper part of the upper surface of the improved site A. The horizontal drainage material 12 'As long as it has a passage function capable of moving water and air in the length direction (horizontal direction) of the horizontal drainage material 12', it may be a linear shape, a strip shape, or a planar shape. However, the horizontal drainage material 12 Its inlet (such as a hole or a slit) through which the water and air sucked from the improved site A side through the aforementioned vertical drainage material 11 is preferably not blocked by sand, sand, etc. in the site. A structure in which water and air easily enter the inside of the horizontal drainage material 12 or a structure in which the passageway is not blocked by the sand or sand in the improved site A and the water and air can move β. In the embodiment shown in Fig. 1, the same structure (composed of a synthetic resin net and a non-woven fabric covering the surface of the synthetic resin net) as the aforementioned vertical drainage material 11 is used. In this state, water and air enter from the non-woven fabric side covering the synthetic resin mesh, and move through the gap between the synthetic resin mesh and the nonwoven fabric, and between the fibers constituting the nonwoven fabric. A water collecting pipe 13 is connected to a necessary portion of the aforementioned horizontal drainage material 12. The water collecting pipe 13 is a perforated pipe (PVC pipe in the figure) with a large number of holes on the pipe peripheral surface. 9 1221166 is connected at one end side of the aforementioned water collecting pipe 13 through a vacuum tank 14 disposed outside the improved site A (outside the construction site). Vacuum pump 15. The vacuum pump 15 which generates a vacuum pressure and serves as a vacuum generating mechanism is not particularly limited, and may be any device selected in consideration of improving the scale of the site or the required vacuum pressure. The vacuum pump 15 in FIG. 1 is a water-tight vacuum pump. Above the improved site A, the upper end of the vertical drainage material 11, the horizontal drainage material 12 and the water collecting pipe 13 are covered with airtight sheets 10, so that the vacuum pressure generated by the vacuum pump 15 passes through the vacuum tank 14, the water collecting pipe 13, The horizontal drain and water material 12 and the vertical drain material 11 can be reliably transported to the improved site A and the improved site A. The airtight sheet 10 shown in Fig. 1 is a pinhole-preventing film formed by laminating a synthetic resin film on a fibrous substrate such as a nonwoven fabric or a woven fabric. In addition, the drainage path of the improved device shown in Fig. 1 includes a drainage groove 16 disposed in the improved site A under the water collecting pipe 13 and passing to the outside of the improved site A. The aforementioned drainage groove 16 is connected to the improved site under the water collecting pipe 13 through the separator 17. Furthermore, the gap water sucked out of the self-improving ground * pan A of the water collecting pipe 13 is separated from the air by the separator 17 and flows into the drainage groove 16 under the water collecting pipe 13 by gravity, and is stored in the drainage groove 16. As shown in FIG. 1, a drainage pump 18 is built in the drainage tank 16, and the water stored in the drainage tank 16 is connected to the drainage pipe 20 of the drainage tank 16 through a connecting pipe 19 to be forcibly discharged outside the improvement site A. . In addition, the shape or size of the drainage groove 16 can be arbitrarily designed as long as consideration is given to improving the scale of the site or the type of site. The type of the drainage pump 18 built in the drainage tank 10 1221166 16 may be any type, as long as the scale of the construction site, the type of construction site, or the price is taken into consideration. The drainage tank 16 may be provided with a measuring device for measuring the amount of water in the gap flowing into the tank. It is also possible to install a water level detection device in the drainage tank 16 and add a control device that enables the drainage pump 18 to operate automatically. In addition, the connecting pipe 19 and the drainage pipe 20 are conduits for draining the gap water sucked from the improved site A to the outside of the improved site A (that is, 'outside the construction site'). The installation position may be any place. The water collecting pipe 13 is also on the lower side. Also, the larger the diameter of the connecting pipe 19 and the drain pipe 20, the higher the drainage efficiency and efficiency, but the more difficult the installation work is. Therefore, it should be appropriately determined in consideration of improving the site scale or site type. Furthermore, in the embodiment shown in FIG. 1, in order to prevent backflow of the gap water discharged from the site, a check valve 2 is provided in the connecting pipe 19 and the drain pipe 20. If the improved device shown in FIG. 1 is used, Most of the air and interstitial water sucked from the improved site A along with the vacuum pressure load are respectively drained from the vacuum pressure transmission path (ie, * arranged in the improved site A under the water collecting pipe 13) The drainage groove 16, the connection pipe 19, and the drainage pipe 20) are discharged out of the improvement site A. In addition, part of the air and interstitial water from the improved site A is discharged into the vacuum tank 14 through the vertical drainage material 11, the horizontal drainage material 12, and the water collection pipe 13 connecting the drainage materials through the vacuum pressure transmission path. In this gap, water is discharged out of the improved site A (device) by the drainage pump 18 disposed in the aforementioned vacuum tank 14, and air is discharged out of the improved site A (device 11 1221166) by the vacuum pump 15. When a water-tight vacuum pump is used as the vacuum pump 14 as the vacuum pressure generating mechanism, it is preferable to use a vacuum tank 14 having a circulating cooling water tank 30 for water sealing as shown in FIG. When using a water-tight vacuum pump, it is necessary to supply cooling water for water sealing to the aforementioned water-tight vacuum pump. However, as described above, if the improved device of the present invention is used, most of the air and interstitial water sucked out of the improved site A with the vacuum pressure load will pass through the drainage paths (each separate from the vacuum pressure transmission path) That is, the drainage groove 16, the connecting pipe 19, and the drainage pipe® 20) arranged in the improved site A under the water collecting pipe 13 are discharged out of the improved site A, so they are discharged into the vacuum tank 14 through the vacuum pressure transmission path. Very little air and interstitial water. Therefore, when the amount of interstitial water decreases with the improvement of the site, of course, the amount of interstitial water discharged into the vacuum tank 14 will also decrease, and the interstitial water for water sealing cannot be supplied to the vacuum pump 15. At this time, the efficiency of the vacuum pump 15 will be generated. Disadvantages gradually reduced. If the vacuum pump 15 shown in FIG. 2 is used, the circulating cooling water tank 30 for water sealing is provided, and the circulating cooling water for water sealing is supplied to the vacuum pump 15 through the cooling water circulation * pump 32. Therefore, the vacuum pump 15 can always ensure sufficient Therefore, the efficiency of the vacuum pump 15 will not be gradually reduced. The cooling water circulation path of the vacuum tank 14 is provided with a cooling condenser 31 to cool the cooling water during the circulation. In addition, the front end of the drain pipe 20 is connected to the bottom of the vacuum tank 14 shown in FIG. 2, and the gap water from the improved construction site A is discharged into the vacuum tank 14. The water temperature of the gap water from the improved site A is very low. Therefore, the gap water drained into the vacuum tank 14 12 1221166 can be used as the cooling water of the vacuum 杲 15, and the vacuum tank 14 is used to cool the cooling water. The use of the condenser 31 is basically unnecessary, and the use of the cooling condenser 31 can be reduced. Further, in the improved device of the present invention, a ventilation path for sending atmospheric or compressed air into the improved site A and / or the improved site peripheral portion B can be provided. In the improved device shown in Fig. 3, a plurality of drainage pipes 40 are provided at a plurality of locations on the improvement site A (surface layer portion or inside the site). Drain pipe 40—The end passes through the ground water collecting pipe 43, the blower 41 and the air volume control mechanism 42, and is connected to the outside atmosphere; the vacuum pressure (for example, below 0.4 atmosphere) is controlled within a predetermined range. The compressed air within the range is sent to the improvement site In A, the vacuum pressure is transmitted to the improved site A through the drain pipe 40, the water collecting pipe 43, the blower 41, and the control mechanism 42. Thereby, the interstitial water in the improved site A (surface layer or inside the site) provided with the drainage pipe 40 is replaced with the air sent in to reduce the water level, and the plasticization and desaturation of the improved site A are promoted. In addition, by introducing air, the pressure at the vacuum area of the improved construction site A with less depression deformation becomes unbalanced and forced drainage is promoted. Therefore, the improvement effect of the construction site is more effectively improved. * Moreover, in the improved device shown in Fig. 3, the compressed air sent to the improved site A can be fed continuously or intermittently. Moreover, in the embodiment of FIG. 3, the drain pipe 40 having the blower 41 is used to force the compressed air into the improved site A. However, the present invention is not limited to this, and the drain pipe 40 is only arranged in the improved site A alone. It is also possible to make air leak. The improved device shown in FIG. 4 is arranged in a plurality of places in the peripheral portion B of the improved site (preferably within a few meters from the improved site A, at a distance of 0.3 to 1 meter between 13 and 1 row. ) Drain pipe 40. Further, each drain pipe 40 is connected to a water collecting pipe 43 having a valve (not shown) at an end portion, and the inside and outside air of the peripheral portion B of the improved construction site is communicated by opening and closing the valve (not shown). In addition, the upper end of the drain pipe 40 and the water collecting pipe 43 are returned with clay to ensure air tightness. Therefore, the clearance water in the peripheral portion B of the improved construction site where the drainage pipe 40 is disposed is opened and closed by a valve (not shown), and passes through each drainage pipe 40 and the water collection pipe 43 to evaporate and leak with the leaked air, thereby improving the periphery of the construction site. The groundwater in the part B will be reduced, which will improve the plasticization and desaturation of the peripheral part B of the construction site, especially the surface layer part, and make it harder. As a result, a trimming effect is generated between the improved site A and the improved site peripheral portion B, and the influence of the improved site improvement on the improved site peripheral portion B is alleviated, and only the improved site A sinks. In the improved device shown in FIG. 5, a plurality of firsts are connected to the necessary positions of the water collecting path of the water collecting pipe 53 connected to each of the vertical drainage materials 51 provided at a predetermined distance in the improved site A through the horizontal drainage material 52. Drain tank 54 (refer to FIG. 6). The water collecting pipe 53 is connected to a position above the first drainage tank 54, and the water concentrated in the gaps of the water collecting pipe 53 is discharged to each of the first drainage tanks 54. Moreover, as for the improved device shown in FIG. 5, similarly to the device shown in FIG. 1, the upper surface of the improved site and the upper end of the vertical drainage material 51, the horizontal drainage material 52, and the water collecting pipe 53 are all covered with the airtight sheet 50. The vacuum pressure generated by the vacuum pump (not shown) passes through the vacuum tank (not shown), the water collecting pipe 53, the horizontal drainage material 52, and the vertical drainage material 51, and is surely transmitted to the upper surface of the improved site A and the inside of the improved site A. 14 1221166 The aforementioned device has a second drainage groove 55 (refer to FIG. 7) leading to the improved site A (that is, outside the construction site) connected to the necessary position of the water collecting pipe 53 water collecting path; It communicates with the first drainage groove 54 and between the first drainage groove 54 through a communication pipe 56 connected to the lower portion of the first drainage groove 54 and the second drainage groove 55. The interstitial water discharged to each first drainage tank 54 is discharged to the second drainage tank 55 through the communication pipe 56. The gap water in the second drainage tank 55 is forcibly discharged through a drainage pipe 58 by a drainage pump 57 built in the second drainage tank 55. Further, in order to prevent the backwater from flowing backward, a check valve 59 is provided on the drain pipe 58 β. In addition, the air sent to the second drainage tank 55 together with the interstitial water through the water collecting pipe 13 is discharged through the exhaust pipe 60 connected to the vacuum tank 14. Then, the improved device shown in FIGS. 8 to 10 is shown. Explain. In the improved device shown in Figs. 8 to 10, the horizontal drainage material 72 and the water collecting pipe 73 both have a transmission structure for transmitting vacuum pressure and a drainage structure for discharging interstitial water, and constitute a drainage path together with a drainage groove. Independent of vacuum * pressure transmission path. That is, the horizontal drainage material 72 has two passages (a vacuum pressure transmission path and a drainage path) for moving air and water in the longitudinal direction (horizontal direction) of the horizontal drainage material 72. In the embodiment shown in FIG. 8, the same structure as the aforementioned vertical drainage material 71 (composed of a synthetic resin net and a non-woven fabric covering the synthetic resin net) is used to fold it into two folds in the longitudinal direction, and the inner side is sandwiched. The upper end portion of the vertical drainage material 71 is thereby connected to the vertical drainage material 71. 15 1221166 The flap portion 72a on the lower side of the horizontal drainage material 72 serves as a water discharge path for gap water, and the flap portion 72b on the upper side serves as a vacuum pressure transmission path. In addition, the gap water sucked from the improved site by the vertical drainage material 71 will flow into the flap portion 72a on the lower side of the horizontal drainage material 72 due to gravity, and as a drainage path, it moves along the horizontal drainage material 72 and is discharged to the water collecting pipe 73. . In addition, the vacuum pressure (air) generated by the vacuum pump (not shown) is light. Therefore, the flap portion 72b on the upper side of the horizontal drainage material 72 is used as the transmission path, and the horizontal drainage material 72 is moved to the vertical drainage material 71. Similarly to the horizontal drainage material 72, the water collection pipe 73 has a vacuum pressure transmission structure and a drainage structure for discharging interstitial water. As shown in FIG. 9, a perforated pipe (PVC pipe shown in the figure) is provided with a large number of holes on the pipe peripheral surface. Inside the pipe, a partition wall 73a for separating the pipe from top to bottom and having a perforation is provided. The upper side of 73a is a vacuum pressure transmission path ', and the lower side of the aforementioned partition wall 73a becomes a drainage path for gap water. In addition, as shown in the figure, a check valve 73b is provided at the through hole of the partition wall 73a to prevent gravity from flowing into the gap between the lower side of the partition wall 73a and backflow to the upper side of the partition wall 73a. In the improved device shown in Figs. 8 to 10, the horizontal drainage material 72 and the water collecting pipe 73 have a vacuum pressure transmission structure and a drainage structure for discharging interstitial water. Therefore, they are configured together with the drainage tank and the vacuum pressure transmission path. The independent drainage path can discharge the gap water more efficiently. Next, the weak site improvement method (hereinafter referred to as "improvement method") of the present invention will be described. The modified method used in the device shown in Fig. 1 is as follows. First, the vertical drainage material 11 is installed in the improved site A at predetermined intervals. The distance between the vertical drainage materials 11 is set to a range within which the applied vacuum pressure 16 1221166 can be transmitted, specifically, about 1 meter. The vertical drainage material 11 is installed in the state that the vertical drainage material 11 is inserted into the mandrel (not shown) into the improved site A, and the mandrel is left under the vertical drainage material 11 in the improved site A (Not shown) retrieve. In this way, by arranging the vertical drainage materials 11 at a predetermined distance in the improved site A, vertical drainage columns at predetermined distances will be formed in the improved site A. The vertical drainage materials 11 constituting these drainage columns will form a vacuum pump. The vacuum pressure generated by 15 will be transmitted to the improved site A. At the same time, the water and air contained in the improved site A between the drainage columns are also sucked up by using the vertical discharge β water material 11 as the drainage path. A horizontal drainage material 12 is connected to the vertical drainage material 11. The vertical drainage material 11 is driven into the improved construction site A, and its upper end portion 11a protrudes from the upper surface of the improved construction site A. The horizontal drainage material 12 is arranged in parallel so as to contact the above-mentioned projection 11a. The water collecting pipe 13 is connected to the necessary place of the horizontal drainage material 12 mentioned above. The water collecting pipe 13 is a perforated pipe provided with a large number of holes on its peripheral surface. The one end of the aforementioned water collecting pipe 13 is connected to the vacuum pump 15 through a vacuum tank 14 disposed outside the improved site A (that is, outside the construction site). Further, the vacuum pressure generated by the vacuum pump 15 is transmitted to the water collecting pipe 13 through the vacuum tank 14, and the 'vacuum pressure is transmitted to the improved site A through the horizontal drainage material 12 and the vertical drainage material 11' connected to the aforementioned water collection tube 13. Further, in the improved construction method of the present invention, after the vertical drainage material 11 is provided, the horizontal drainage material 12 is arranged, and the water collecting pipe is provided, the upper surface of the improved site A is erected with the upper end of the vertical drainage material, the horizontal drainage material 12 and the water collecting pipe 13 17 1221166 is covered with the airtight sheet 10 together, so that the vacuum pressure generated by the vacuum pump 15 can be surely transmitted to the improved site A and the improved site. In this way, in the improvement method using the improvement device shown in FIG. 1, the vacuum pressure generated by the vacuum pump 15 is transmitted to the vacuum tank 14, the water collecting pipe 13, the horizontal drainage material 12 and the vertical drainage material 11, and the vertical drainage material 11 is contained therein. Achieved a predetermined degree of decompression (below 0.4 atmospheres). In addition, the vacuum pressure in the vertical drainage material 11 is transmitted to the site A around the vertical drainage material 11, and the surrounding site A with the vertical drainage material 11 as the center is in a decompressed area (hereinafter referred to as "decompression area"). . The vacuum pressure is transmitted from the site A around the vertical drainage material 11 which becomes the decompression area, and then transported to the surrounding site A. Pressure (water pressure, earth pressure) will occur toward the site A around the vertical drainage material 11. As the site is pressurized, the clearance water contained in the site A around the vertical drainage material 11 is sucked out toward the vertical drainage material 11 and discharged through the vertical drainage material 11, the horizontal drainage material 12 and the water collecting pipe 13, and around the vertical drainage material 11 The outside of the site A also becomes a decompression area. In this way, the decompression area will be expanded to the surrounding site A with the vertical drainage material 11 as the center. Soon, the entire area of the improved site A will become a decompression area. The increase in strength will be carried out, and the compaction and strength of the entire area of the improved site A will be improved. In addition, the interstitial water sucked from the improved construction site A is discharged through the following drainage path. That is, the clearance water of the improvement site A is sucked out by the vertical drainage material 11 and the horizontal drainage material 12 and temporarily flows into the water collecting pipe 13. As shown in FIG. 1, a drainage tank 16 is connected to the transmission site 18 1221166 in the improved site A under the water collecting pipe 13. The water concentrated in the gap of the water collecting pipe 13 is separated from the air by the separator Π, and flows into the drainage groove 16 under the water collecting pipe 13 by gravity, and is stored in the drainage groove 16. With the drainage of the interstitial water in the improved construction site A, the construction site A is compressed and subsided. When the ground plate A is subsided, a height difference is generated between the vacuum groove 14 provided on the ground surface and the drainage groove 16 provided on the ground surface A. When the aforementioned height difference exceeds 10 meters, if the aforementioned vacuum pressure drainage method is used, the gap water in the site A cannot be discharged. The reason is that the limit of vacuum pumping power at 1 atmosphere is 10 meters. Therefore, the more the site A subsides, the lower the vacuum pumping power of the vacuum pump 15 and the lower the drainage efficiency. A drainage pump 18 is built into the drainage tank 16 shown in FIG. 1, and the clearance water stored in the drainage tank 16 passes through the drainage pipe 20 (connected to the drainage tank 16 through the connecting pipe 19) and is forcibly discharged to the improvement site. Outside A (that is, outside the construction site). Therefore, the drainage is not affected by the subsidence of the site A, and the improvement of the deep part of the site can be implemented more efficiently and reliably. The drainage groove 16 may be provided at a position below the water collecting pipe 13 so that the water in the water collecting pipe 13 flows due to gravity. * When using the drainage tank 16 with the drainage pump 18 built in, the sinking of the site A does not affect the drainage. Therefore, after the decompression area in the site A is made by vacuum pressure, if the vacuum pressure is continuously applied, the improvement will be improved. The moisture contained in the site, especially the surface layer of the site (from the surface to a depth of 1 to 2 meters), will evaporate and the site will become unsaturated soil. The so-called "unsaturated soil" does not cause excess interstitial water pressure due to the downward pressure load of the mound, etc., and the material is stronger than saturated soil. Therefore, even after the decompression area is made, the site that continues to apply 19 1221166 vacuum pressure, especially the desaturation of the surface layer of the site, is more dangerous than the situation where the site is being improved or soil is piled up after the site is improved. Will be greatly reduced. In addition, when the drainage tank 16 with the drainage pump 18 is used, the vacuum pressure can be transmitted regardless of the degree of improvement of the site. Therefore, if the vacuum pressure is continuously applied after the site is not saturated, the moisture in the site will be further removed. , The site changes from an unsaturated state to a very hard and stable plasticized state. Moreover, in the embodiment shown in the drawing, a drainage pump 18 is built in the drainage tank 16 to forcibly discharge the water stored in the drainage tank 16 to the outside of the device. However, because the scale of the site or the type of site has been improved, It is also possible to use a drain tank 16 without a built-in drain pump 18 at this time. Moreover, in the embodiment shown in the drawing, although the inside of the vertical drainage material 11 is made to be 0.4 atmospheres or less by the vacuum pressure generated by the vacuum pump 15, it is not limited to this, and it may be considered to improve the weakness of the construction site, for example Site water content, etc., and properly determine the size of the vacuum pressure. In the improvement method using the improvement device shown in Figs. 5 to 7, in the water collecting path of the water collecting pipe 53 connected through the horizontal drainage material 52 through each vertical drainage material 51 provided at a predetermined distance from the * improvement site A, A plurality of first drainage grooves 54 and a second drainage groove 55 leading to the outside of the improved site are connected, and the first drainage groove 54 and the second drainage groove 55 are connected by a communication pipe 56 and will be concentrated on the foregoing. The gap water in the water collecting pipe 13 is drained to the first drainage tank 54, and the gap water in the first drainage tank 54 is drained to the second drainage tank 55, and the drainage pump built in the second drainage tank 55 is drained. 57 20, forcibly draining the gap water in the second drainage tank 55. In the improvement method using the improvement device shown in FIGS. 8 to 10, the horizontal drainage material 72 and the water collecting pipe 73 both have a conveying structure for transmitting vacuum pressure and a drainage structure for discharging interstitial water. Therefore, the vertical drainage material is used to improve the site A. The interstitial water sucked out through the horizontal drainage material 72 and the water collecting pipe 73 is provided with a gap water drainage structure which is independent of the vacuum pressure transmission structure, and flows into a drainage groove disposed in the improved site under the water collecting pipe 73 to discharge the improved site. Outside (ie offsite). Moreover, the above-mentioned embodiments are merely illustrative examples. For example, a high vacuum pressure is applied at the beginning of improvement, and then a low vacuum pressure is maintained, or a high and low vacuum pressure is alternately repeated. The scope of the scope can be freely changed. [Effects of the Invention] In the present method of the present invention, drainage grooves are arranged in the improved site under the water collecting pipe connected to each vertical drainage material set at a predetermined distance from the improved site through the horizontal drainage material, and will be concentrated on the collection site. The gap water in the water pipe is drained to the drainage tank, and then the gap water in the drainage tank is drained out of the improved site through a drainage pipe connected to the drainage tank, and a path different from the transmission path for transmitting vacuum pressure is used. Since the clearance water in the improved construction site is discharged, the construction site can be improved more efficiently. In particular, when the drainage pump is built in the drainage tank and the clearance water in the drainage tank is forcibly discharged out of the improved construction site, the drainage can be continued without being affected by the subsidence of the construction site. Therefore, it will not occur when the construction site is subsided. Loss of pumping pressure due to vacuum pressure. Also, if the vacuum pressure is applied to the site to create a decompression zone 21 1221166, the vacuum pressure will continue to improve the site, especially the moisture contained in the surface layer of the site (1 to 2 meters deep from the surface) will evaporate, Will become unsaturated soil. In addition, if the vacuum pressure is continuously applied after the site is desaturated, the moisture in the site will be further removed, and the unsaturated state can be improved to a very hard and stable plasticized site. The improved device of the present invention includes a vertical drainage material provided at a predetermined distance in the improved construction site, a water collecting pipe connected to each of the vertical drainage materials through the horizontal drainage material, and an improved construction site β disposed below the water collecting pipe. The drainage channel outside the improved site uses a different path from the conveying path for transmitting vacuum pressure to the improved site to drain the gap water from the improved site, so the site can be improved more efficiently. In particular, when a drainage pump is hidden in the drainage tank, the gap water in the drainage tank can be forcibly discharged through the drainage pipe, and the drainage can be continuously performed without being affected by the subsidence of the site. Therefore, the pressure is reduced in the site by vacuum pressure. If you continue to apply vacuum pressure after pressing the area, the soil on the improved site, especially the surface layer of the site (1 to 2 meters deep from the surface) will evaporate, and the site will become unsaturated soil. In addition, if the vacuum pressure is continuously applied after the site is desaturated, the moisture in the site will be further removed, and the unsaturated state can be improved to a very hard and stable plasticized site. [Brief description of the drawings] (I) Schematic diagram The figure 1 shows a schematic diagram of the improved device of the present invention. 22 1221166 Figure 2 is an enlarged schematic view showing a circulating cooling water tank for water sealing of an improved device of the present invention. Fig. 3 is a schematic diagram showing another embodiment of the improved device of the present invention. Fig. 4 is a schematic diagram showing another embodiment of the improved device of the present invention. Fig. 5 is a schematic diagram showing another embodiment of the improved device of the present invention. Fig. 6 is an enlarged perspective view showing a first drainage groove in the embodiment shown in Fig. 5; Fig. 7 is an enlarged perspective view showing a second drainage groove in the embodiment shown in Fig. 5; Fig. 8 is a schematic diagram showing another embodiment of the improved device of the present invention. Fig. 9 is a schematic view showing still another embodiment of the improved device of the present invention. Fig. 10 is a schematic diagram showing another embodiment of the improved device of the present invention. Fig. 11 is a schematic diagram showing a conventional improved device. (II) Symbols for components 1 Vertical drainage material 2 Horizontal drainage material 3 Water collecting tube 4 Vacuum tank 5 Vacuum pump 6 Airtight sheet 10 Airtight sheet 11 Vertical drainage material 12 Horizontal drainage material 13 Water collecting tube 23 1221166 14 Vacuum tank 15 Vacuum pump 16 rows Water tank 17 Separator 18 Drain pump 19 Connecting pipe 20 Drain pipe 21 Check valve 30 Circulating cooling water tank for water seal 31 Cooling condenser 32 Cooling water circulation pipe 40 Drain pipe 41 Blower 42 Control mechanism 43 Water collecting pipe 50 Airtight film 51 Vertical drainage material 52 Horizontal drainage material 53 Water collecting pipe 54 First drainage groove 55 Second drainage groove 56 Connecting pipe 57 Drain pump 58 Drain pipe
24 1221166 59 止回閥 60 排氣管 71 垂直排水材 72 水平排水材 73 集水管 11a 突出部 72a 折片部 72b 折片部 73a 隔牆 73b 止回閥 A 改良地盤 B 改良地盤周邊部24 1221166 59 Check valve 60 Exhaust pipe 71 Vertical drainage material 72 Horizontal drainage material 73 Water collecting pipe 11a Protrusion 72a Folding section 72b Folding section 73a Partition wall 73b Check valve A Improved construction site B Improved construction site periphery
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