【正文】 這些實際困難可以采用兩種方法來克服。 就給定的安全系數(shù)而論，所有這些參數(shù)的確定都是以建筑物的最佳成本為依據(jù)的。 至少在理論上，概率法的主要優(yōu)點是可以科學(xué)的考慮所有隨機安全系數(shù)，然后將這些隨機安全系數(shù)組合成確定的安全系數(shù)。 把對應(yīng)于不乘以荷載系數(shù)的活載和恒載的工作（使用）條 件的應(yīng)力與規(guī)定值（使用極限狀態(tài)）相比較。 此外，根據(jù)安全系數(shù)的不同用途，可以把結(jié)構(gòu)的計算方法分為： （ 1）容許應(yīng)力法，在這種方法中，把結(jié)構(gòu)承受最大荷載時計算得到的應(yīng)力與經(jīng)過按規(guī)定的安全系數(shù)進行折減后的材料強度作比較。 （ 2）使用極限狀態(tài)，它對應(yīng)著結(jié)構(gòu)的使用功能和耐久性。這個比值還與結(jié)構(gòu)的破壞概率（危險率）成反比。必須記住翻斗車與自卸卡車之間的區(qū)別。最小的翻斗車的容量大約為 立方米，而最大的標(biāo)準(zhǔn)型翻斗車的容量大約為 179。最大的自行式鏟運機鏟斗容量為 19立方米（滿載時為 25 m179。在挖掘硬土?xí)r，人們發(fā)現(xiàn)在開挖場地經(jīng)常用一輛助推拖拉機（輪式或履帶式），對返回挖土的鏟運機進行助推這種施工方法是經(jīng)濟的。每種機械設(shè)備應(yīng)該進行最適合它的性能的作業(yè)。拉鏟挖土機的缺點是只能挖比它本身低的土，不能施加壓力挖入壓實的土壤內(nèi)，不能在陡坡上挖土，而且挖。拉鏟挖土機。根據(jù)現(xiàn)有的地圖和標(biāo)高，道路工程師應(yīng)在設(shè)計繪圖室中的工作也并不是徒勞的。一般說來，有關(guān)挖土機、裝載機和運輸機械的唯一可靠而又最新的資料可以從制造廠商處獲得。在 1935 年，目前采用的利用輪胎式機械設(shè)備進行土方挖運的方法大多數(shù)還沒有出現(xiàn)。 選擇混凝土截面時，采用試算與調(diào)整過程可以使復(fù)核與設(shè)計結(jié)合在一起。因此，在選擇混凝土截面時需要進行試算并作調(diào)整，根據(jù)施工現(xiàn)場條件、混凝土原材料的供應(yīng)情況 、業(yè)主提出的特殊要求、對建筑和凈空高度的要求、所用的設(shè)計規(guī)范以及建筑物周圍環(huán)境條件等最后確定截面。F 以上的條件下。澆筑基礎(chǔ)前，應(yīng)將坑底土夯實并用水浸濕 6英寸，以免土壤從新澆的混凝土中吸收水分。因混凝土由配料攪拌成濕拌合物，經(jīng)過振搗并凝固硬化，可以做成任何一種需要的形狀。因此，截面的受拉區(qū)必須配置抗拉鋼筋和抗剪鋼筋以增加鋼筋混凝土構(gòu)件中較弱的受拉區(qū)的強度。 關(guān)鍵詞：混凝土，土方工程 ， 結(jié)構(gòu)安全度 素混凝土是由水泥、水、細(xì)骨料、粗骨料（碎石或；卵石）、空氣，通常還有其他外加劑等經(jīng)過凝固硬化而成。 (2) Amortization funds for the duration of the construction。 (4)Uncertainty related to the approximation of the putational method used ( deviation of the actual stresses from puted stresses ). Furthermore, probabilistic theories mean that the allowable risk can be based on several factors, such as : (1) Importance of the construction and gravity of the damage by its failure。 large vibrations。 failure by fatigue。. Special types include the selfloading dumper of up to 4 m 179。 heaped. The largest selfpropelled scrapers are of 19 m 179。1 2 外文翻譯 Introduction to reinforced concrete and earth works Abstract： As a designer must first clear the building structure itself was designed and intensity levels, as well as related issues indepth discussion and research, this paper describes on the reinforced concrete, earthwork engineering knowledge, let more indepth understanding of this Discusses the key, and the rational application of knowledge to help us design more excellent building Keywords: concrete, earthwork, structural safety Reinforced Concrete Plain concrete is formed from a hardened mixture of cement ,water ,fine aggregate, coarse aggregate (crushed stone or gravel),air, and often other admixtures. The plastic mix is placed and consolidated in the formwork, then cured to facilitate the acceleration of the chemical hydration reaction lf the cement/water mix, resulting in hardened concrete. The finished product has high pressive strength, and low resistance to tension, such that its tensile strength is approximately one tenth lf its pressive strength. Consequently, tensile and shear reinforcement in the tensile regions of sections has to be provided to pensate for the weak tension regions in the reinforced concrete element. It is this deviation in the position of a reinforces concrete section from the homogeneity of standard wood or steel sections that requires a modified approach to the basic principles of structural design. The two ponents of the heterogeneous reinforced concrete section are to be so arranged and proportioned that optimal use is made of the materials involved. This is possible because concrete can easily be given any desired shape by placing and pacting the wet mixture of the constituent ingredients are properly proportioned, the finished product bees strong, durable, and, in bination with the reinforcing bars, adaptable for use as main members of any structural system. 2 The techniques necessary for placing concrete depend on the type of member to be cast: that is, whether it is a column, a bean, a wall, a slab, a foundation. a mass columns, or an extension of previously placed and hardened concrete. For beams, columns, and walls, the forms should be well oiled after cleaning them, and the reinforcement should be cleared of rust and other harmful materials. In foundations, the earth should be pacted and thoroughly moistened to about 6 in. in depth to avoid absorption of the moisture present in the wet concrete. Co