本文選題：黃土 + 濕陷性�。� 參考：《長安大學(xué)》2015年碩士論文

【摘要】：在工程建設(shè)和施工的過程中,常常會(huì)遇到一些棘手的工程問題,如濕陷性黃土。濕陷性黃土呈現(xiàn)出了高強(qiáng)度的結(jié)構(gòu)模式,在與水相遇時(shí),會(huì)極速濕陷、軟化。所以,為了保障黃土地區(qū)工程建設(shè)安全,必須要解決好濕陷性黃土問題。這些年來,隨著工程建設(shè)的加快,人們也進(jìn)一步的了解了濕陷性黃土的成因、物理特性、分布形態(tài)、強(qiáng)度指標(biāo)、化學(xué)性質(zhì)、影響因素等情況。當(dāng)前,在工程建設(shè)中,人們治理濕陷性黃土的措施包括:①路基加固法;②排水固結(jié)法;③深層密實(shí)法;④換填墊層法;⑤化學(xué)加固法;⑥置換法;⑦其余方法。在設(shè)計(jì)和施工環(huán)節(jié),會(huì)面對(duì)多種類別的濕陷性黃土,需要在剖析此段濕陷性黃土的性質(zhì)之后,再采取針對(duì)性的措施,以特殊的處理工藝確保路基質(zhì)量。本文的研究對(duì)象為寧夏桃同高速公路,在分析了其所處區(qū)域內(nèi)的濕陷性黃土的特性之后,結(jié)合桃同公路病害現(xiàn)狀提出了:(1)以“防排結(jié)合、減小濕陷”為目的,通過在路基兩側(cè)設(shè)置夯實(shí)水泥土樁,并恢復(fù)全線排水設(shè)施,以防地表水通過路基兩側(cè)及路基坡面下滲至路基基底;(2)以“擠密加固、提高強(qiáng)度”為目的,通過在路基沉陷嚴(yán)重段落和橋涵臺(tái)背處設(shè)置旋噴樁,以消弱基底黃土的濕陷性和提高路基承載力;(3)以“恢復(fù)功能、確保安全”為目的,通過改善路基和橋頭差異沉降路段的平整度,并對(duì)沿線中央帶和路側(cè)護(hù)欄進(jìn)行整治,以確保全線行車舒適性和安全性的公路路基病害處置方案。本項(xiàng)目主要使用濕陷性黃土地基處理技術(shù)中的夯實(shí)水泥土樁、水泥土隔水墻、高壓噴射注漿為主的具體路基沉陷病害處治措施:1)自重濕陷等級(jí)為Ⅲ級(jí)和Ⅳ級(jí)路段:基底進(jìn)行高壓噴射注漿(旋噴樁)處理,樁體應(yīng)穿透濕陷性黃土層,同時(shí)在坡腳處設(shè)置φ80cm夯實(shí)水泥土樁;(2)自重濕陷等級(jí)為Ⅱ級(jí)且處于濕陷性等級(jí)Ⅲ級(jí)和Ⅳ級(jí)前后的沉陷較嚴(yán)重路段:坡腳處設(shè)置φ80cm夯實(shí)水泥土樁;(3)濕陷等級(jí)低于自重濕陷Ⅱ級(jí)或自重濕陷等級(jí)為Ⅱ級(jí)但地基已趨于穩(wěn)定且兩側(cè)為旱地的路段:不做處理。(4)其他路段設(shè)置2m深、80cm厚的水泥土隔水墻,起隔水作用。在此基礎(chǔ)上根據(jù)設(shè)計(jì)方案,提出了濕陷性黃土地基處理技術(shù)在寧夏桃同高速公路中的現(xiàn)場實(shí)施施工內(nèi)容:主要包括:夯實(shí)水泥土樁、水泥土隔水墻、高壓噴射注漿在具體項(xiàng)目施工中的施工工藝、注意事項(xiàng)以及具體的質(zhì)量控制方案。作者認(rèn)為這幾項(xiàng)處理方法在寧夏地區(qū)的其他高速路上濕陷性黃土的處理當(dāng)中同樣適用,但各種濕陷性黃土的處理方法各有其特點(diǎn)及應(yīng)用范圍,在施工中應(yīng)靈活掌握,需要施工人員在工作中靈活應(yīng)用,從實(shí)際出發(fā),考慮工期要求、環(huán)境特性、土層厚度等因素,尋找出一條最合理、經(jīng)濟(jì)、快速的處理措施。
[Abstract]:In the process of engineering construction and construction, some difficult engineering problems, such as collapsible loess, are often encountered. Collapsible loess presents a high strength structural pattern. When it meets with water, it collapses and softens. Therefore, in order to ensure the safety of engineering construction in loess area, we must solve the problem of collapsible loess. Over the years, with the acceleration of engineering construction, people also further understand the causes of collapsible loess, physical characteristics, distribution form, strength index, chemical properties, influencing factors and so on. At present, in the engineering construction, the measures for controlling collapsible loess include: 1 subgrade reinforcement method, 2 drainage consolidation method, 3 deep layer compaction method, 4 replacement cushion method, 5 chemical reinforcement method, 6 replacement method and 7 other methods. In the process of design and construction, many kinds of collapsible loess will be faced. After analyzing the nature of collapsible loess in this section, some targeted measures should be taken to ensure the quality of roadbed with special treatment technology. After analyzing the characteristics of collapsible loess in the area of Taotong Expressway in Ningxia, combining with the present condition of the disease of Taodong Highway, this paper puts forward that the purpose of this paper is to "combine prevention and treatment and reduce the collapsibility". By setting up rammed cement soil piles on both sides of the roadbed and restoring the drainage facilities of the whole line, to prevent the surface water from seeping to the subgrade base through both sides of the roadbed and the slope of the subgrade, the purpose of "compaction and reinforcement and improvement of the strength" is taken as the purpose. In order to reduce the collapsibility of loess foundation and improve the bearing capacity of subgrade, the purpose of this paper is to restore function and ensure safety by setting rotary jet pile in serious section of subgrade settlement and at the back of bridge and culvert abutment, so as to reduce collapsibility of loess base and improve bearing capacity of roadbed. By improving the smoothness of the subgrade and bridge head differential settlement section and renovating the central belt and side guardrail along the road to ensure the comfort and safety of the whole road roadbed disease disposal scheme. This project mainly uses the rammed cement-soil pile in the collapsible loess foundation treatment technology, the cement soil water barrier wall, Treatment measures of concrete roadbed subsidence Diseases mainly by High pressure Jet grouting; the grade of deadweight collapsibility is grade 鈪，

本文編號(hào)：1974038